CA2034293C - Process for production of water-absorbent resin - Google Patents
Process for production of water-absorbent resinInfo
- Publication number
- CA2034293C CA2034293C CA002034293A CA2034293A CA2034293C CA 2034293 C CA2034293 C CA 2034293C CA 002034293 A CA002034293 A CA 002034293A CA 2034293 A CA2034293 A CA 2034293A CA 2034293 C CA2034293 C CA 2034293C
- Authority
- CA
- Canada
- Prior art keywords
- water
- process according
- polymerization
- stage
- ethylenic unsaturated
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 239000002250 absorbent Substances 0.000 title claims abstract description 71
- 229920005989 resin Polymers 0.000 title claims abstract description 66
- 239000011347 resin Substances 0.000 title claims abstract description 66
- 238000000034 method Methods 0.000 title claims abstract description 30
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 9
- 238000006116 polymerization reaction Methods 0.000 claims abstract description 84
- 239000000178 monomer Substances 0.000 claims abstract description 48
- 239000007864 aqueous solution Substances 0.000 claims abstract description 34
- 239000004094 surface-active agent Substances 0.000 claims abstract description 27
- 239000000084 colloidal system Substances 0.000 claims abstract description 25
- 230000001681 protective effect Effects 0.000 claims abstract description 25
- 238000010557 suspension polymerization reaction Methods 0.000 claims abstract description 20
- 239000003431 cross linking reagent Substances 0.000 claims abstract description 19
- 239000007870 radical polymerization initiator Substances 0.000 claims abstract description 14
- 239000002904 solvent Substances 0.000 claims abstract description 14
- 238000001816 cooling Methods 0.000 claims abstract description 7
- 239000003209 petroleum derivative Substances 0.000 claims abstract description 7
- 239000000243 solution Substances 0.000 claims description 43
- IMNFDUFMRHMDMM-UHFFFAOYSA-N N-Heptane Chemical compound CCCCCCC IMNFDUFMRHMDMM-UHFFFAOYSA-N 0.000 claims description 35
- NIXOWILDQLNWCW-UHFFFAOYSA-N acrylic acid group Chemical group C(C=C)(=O)O NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 claims description 35
- -1 sorbitan fatty acid esters Chemical class 0.000 claims description 26
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 claims description 9
- 235000014113 dietary fatty acids Nutrition 0.000 claims description 9
- 239000000194 fatty acid Substances 0.000 claims description 9
- 229930195729 fatty acid Natural products 0.000 claims description 9
- 239000004698 Polyethylene Substances 0.000 claims description 8
- 229920000573 polyethylene Polymers 0.000 claims description 8
- 229920001223 polyethylene glycol Polymers 0.000 claims description 8
- HRPVXLWXLXDGHG-UHFFFAOYSA-N Acrylamide Chemical group NC(=O)C=C HRPVXLWXLXDGHG-UHFFFAOYSA-N 0.000 claims description 7
- UWFRVQVNYNPBEF-UHFFFAOYSA-N 1-(2,4-dimethylphenyl)propan-1-one Chemical group CCC(=O)C1=CC=C(C)C=C1C UWFRVQVNYNPBEF-UHFFFAOYSA-N 0.000 claims description 6
- XDTMQSROBMDMFD-UHFFFAOYSA-N Cyclohexane Chemical compound C1CCCCC1 XDTMQSROBMDMFD-UHFFFAOYSA-N 0.000 claims description 6
- 239000001856 Ethyl cellulose Substances 0.000 claims description 6
- ZZSNKZQZMQGXPY-UHFFFAOYSA-N Ethyl cellulose Chemical compound CCOCC1OC(OC)C(OCC)C(OCC)C1OC1C(O)C(O)C(OC)C(CO)O1 ZZSNKZQZMQGXPY-UHFFFAOYSA-N 0.000 claims description 6
- 239000002202 Polyethylene glycol Substances 0.000 claims description 6
- 229920001249 ethyl cellulose Polymers 0.000 claims description 6
- 235000019325 ethyl cellulose Nutrition 0.000 claims description 6
- VLKZOEOYAKHREP-UHFFFAOYSA-N n-Hexane Chemical compound CCCCCC VLKZOEOYAKHREP-UHFFFAOYSA-N 0.000 claims description 6
- USHAGKDGDHPEEY-UHFFFAOYSA-L potassium persulfate Chemical group [K+].[K+].[O-]S(=O)(=O)OOS([O-])(=O)=O USHAGKDGDHPEEY-UHFFFAOYSA-L 0.000 claims description 6
- FPYJFEHAWHCUMM-UHFFFAOYSA-N maleic anhydride Chemical class O=C1OC(=O)C=C1 FPYJFEHAWHCUMM-UHFFFAOYSA-N 0.000 claims description 5
- KUDUQBURMYMBIJ-UHFFFAOYSA-N 2-prop-2-enoyloxyethyl prop-2-enoate Chemical group C=CC(=O)OCCOC(=O)C=C KUDUQBURMYMBIJ-UHFFFAOYSA-N 0.000 claims description 4
- CERQOIWHTDAKMF-UHFFFAOYSA-N Methacrylic acid Chemical compound CC(=C)C(O)=O CERQOIWHTDAKMF-UHFFFAOYSA-N 0.000 claims description 4
- 229930006000 Sucrose Natural products 0.000 claims description 4
- STVZJERGLQHEKB-UHFFFAOYSA-N ethylene glycol dimethacrylate Substances CC(=C)C(=O)OCCOC(=O)C(C)=C STVZJERGLQHEKB-UHFFFAOYSA-N 0.000 claims description 4
- ZIUHHBKFKCYYJD-UHFFFAOYSA-N n,n'-methylenebisacrylamide Chemical group C=CC(=O)NCNC(=O)C=C ZIUHHBKFKCYYJD-UHFFFAOYSA-N 0.000 claims description 4
- 229940088644 n,n-dimethylacrylamide Drugs 0.000 claims description 4
- YLGYACDQVQQZSW-UHFFFAOYSA-N n,n-dimethylprop-2-enamide Chemical compound CN(C)C(=O)C=C YLGYACDQVQQZSW-UHFFFAOYSA-N 0.000 claims description 4
- 239000002736 nonionic surfactant Substances 0.000 claims description 4
- 239000005720 sucrose Substances 0.000 claims description 4
- 229920002943 EPDM rubber Chemical class 0.000 claims description 3
- CTQNGGLPUBDAKN-UHFFFAOYSA-N O-Xylene Chemical compound CC1=CC=CC=C1C CTQNGGLPUBDAKN-UHFFFAOYSA-N 0.000 claims description 3
- 150000001447 alkali salts Chemical class 0.000 claims description 3
- FQPSGWSUVKBHSU-UHFFFAOYSA-N methacrylamide Chemical compound CC(=C)C(N)=O FQPSGWSUVKBHSU-UHFFFAOYSA-N 0.000 claims description 3
- 239000008096 xylene Substances 0.000 claims description 3
- DBCAQXHNJOFNGC-UHFFFAOYSA-N 4-bromo-1,1,1-trifluorobutane Chemical compound FC(F)(F)CCCBr DBCAQXHNJOFNGC-UHFFFAOYSA-N 0.000 claims description 2
- FBPFZTCFMRRESA-FSIIMWSLSA-N D-Glucitol Natural products OC[C@H](O)[C@H](O)[C@@H](O)[C@H](O)CO FBPFZTCFMRRESA-FSIIMWSLSA-N 0.000 claims description 2
- 229920000896 Ethulose Polymers 0.000 claims description 2
- 239000001859 Ethyl hydroxyethyl cellulose Substances 0.000 claims description 2
- 239000003945 anionic surfactant Substances 0.000 claims description 2
- 125000004386 diacrylate group Chemical group 0.000 claims description 2
- 235000019326 ethyl hydroxyethyl cellulose Nutrition 0.000 claims description 2
- 239000000600 sorbitol Substances 0.000 claims description 2
- AOBIOSPNXBMOAT-UHFFFAOYSA-N 2-[2-(oxiran-2-ylmethoxy)ethoxymethyl]oxirane Chemical compound C1OC1COCCOCC1CO1 AOBIOSPNXBMOAT-UHFFFAOYSA-N 0.000 claims 1
- 239000005062 Polybutadiene Chemical class 0.000 claims 1
- 229920002857 polybutadiene Chemical class 0.000 claims 1
- 239000002002 slurry Substances 0.000 abstract description 6
- SMZOUWXMTYCWNB-UHFFFAOYSA-N 2-(2-methoxy-5-methylphenyl)ethanamine Chemical compound COC1=CC=C(C)C=C1CCN SMZOUWXMTYCWNB-UHFFFAOYSA-N 0.000 description 31
- 239000002245 particle Substances 0.000 description 29
- 239000000843 powder Substances 0.000 description 24
- 238000009826 distribution Methods 0.000 description 23
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 20
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 18
- 238000010521 absorption reaction Methods 0.000 description 17
- 238000006243 chemical reaction Methods 0.000 description 14
- 230000000052 comparative effect Effects 0.000 description 13
- 241000047703 Nonion Species 0.000 description 12
- 239000000047 product Substances 0.000 description 11
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 description 9
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 8
- 230000002745 absorbent Effects 0.000 description 7
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 6
- DNIAPMSPPWPWGF-UHFFFAOYSA-N Propylene glycol Chemical compound CC(O)CO DNIAPMSPPWPWGF-UHFFFAOYSA-N 0.000 description 6
- 229910001873 dinitrogen Inorganic materials 0.000 description 6
- NIXOWILDQLNWCW-UHFFFAOYSA-M Acrylate Chemical compound [O-]C(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-M 0.000 description 5
- HVUMOYIDDBPOLL-XWVZOOPGSA-N Sorbitan monostearate Chemical compound CCCCCCCCCCCCCCCCCC(=O)OC[C@@H](O)[C@H]1OC[C@H](O)[C@H]1O HVUMOYIDDBPOLL-XWVZOOPGSA-N 0.000 description 5
- 238000009792 diffusion process Methods 0.000 description 5
- 239000000463 material Substances 0.000 description 5
- 239000000203 mixture Substances 0.000 description 5
- PEDCQBHIVMGVHV-UHFFFAOYSA-N Glycerine Chemical compound OCC(O)CO PEDCQBHIVMGVHV-UHFFFAOYSA-N 0.000 description 4
- 229920003171 Poly (ethylene oxide) Polymers 0.000 description 4
- 239000003795 chemical substances by application Substances 0.000 description 4
- GYZLOYUZLJXAJU-UHFFFAOYSA-N diglycidyl ether Chemical class C1OC1COCC1CO1 GYZLOYUZLJXAJU-UHFFFAOYSA-N 0.000 description 4
- 238000002156 mixing Methods 0.000 description 4
- 239000011780 sodium chloride Substances 0.000 description 4
- 239000000126 substance Substances 0.000 description 4
- VZCYOOQTPOCHFL-UHFFFAOYSA-N trans-butenedioic acid Natural products OC(=O)C=CC(O)=O VZCYOOQTPOCHFL-UHFFFAOYSA-N 0.000 description 4
- UHOVQNZJYSORNB-UHFFFAOYSA-N Benzene Chemical compound C1=CC=CC=C1 UHOVQNZJYSORNB-UHFFFAOYSA-N 0.000 description 3
- OFOBLEOULBTSOW-UHFFFAOYSA-N Propanedioic acid Natural products OC(=O)CC(O)=O OFOBLEOULBTSOW-UHFFFAOYSA-N 0.000 description 3
- 239000002253 acid Substances 0.000 description 3
- 150000001875 compounds Chemical class 0.000 description 3
- RTZKZFJDLAIYFH-UHFFFAOYSA-N ether Substances CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 description 3
- 239000012948 isocyanate Substances 0.000 description 3
- VZCYOOQTPOCHFL-UPHRSURJSA-N maleic acid Chemical compound OC(=O)\C=C/C(O)=O VZCYOOQTPOCHFL-UPHRSURJSA-N 0.000 description 3
- 239000011976 maleic acid Substances 0.000 description 3
- 239000001587 sorbitan monostearate Substances 0.000 description 3
- 235000011076 sorbitan monostearate Nutrition 0.000 description 3
- 229940035048 sorbitan monostearate Drugs 0.000 description 3
- 238000003892 spreading Methods 0.000 description 3
- MYRTYDVEIRVNKP-UHFFFAOYSA-N 1,2-Divinylbenzene Chemical compound C=CC1=CC=CC=C1C=C MYRTYDVEIRVNKP-UHFFFAOYSA-N 0.000 description 2
- OZAIFHULBGXAKX-UHFFFAOYSA-N 2-(2-cyanopropan-2-yldiazenyl)-2-methylpropanenitrile Chemical compound N#CC(C)(C)N=NC(C)(C)C#N OZAIFHULBGXAKX-UHFFFAOYSA-N 0.000 description 2
- LEJBBGNFPAFPKQ-UHFFFAOYSA-N 2-(2-prop-2-enoyloxyethoxy)ethyl prop-2-enoate Chemical compound C=CC(=O)OCCOCCOC(=O)C=C LEJBBGNFPAFPKQ-UHFFFAOYSA-N 0.000 description 2
- XFCMNSHQOZQILR-UHFFFAOYSA-N 2-[2-(2-methylprop-2-enoyloxy)ethoxy]ethyl 2-methylprop-2-enoate Chemical compound CC(=C)C(=O)OCCOCCOC(=O)C(C)=C XFCMNSHQOZQILR-UHFFFAOYSA-N 0.000 description 2
- XZIIFPSPUDAGJM-UHFFFAOYSA-N 6-chloro-2-n,2-n-diethylpyrimidine-2,4-diamine Chemical compound CCN(CC)C1=NC(N)=CC(Cl)=N1 XZIIFPSPUDAGJM-UHFFFAOYSA-N 0.000 description 2
- 239000004215 Carbon black (E152) Substances 0.000 description 2
- RGSFGYAAUTVSQA-UHFFFAOYSA-N Cyclopentane Chemical compound C1CCCC1 RGSFGYAAUTVSQA-UHFFFAOYSA-N 0.000 description 2
- 239000004641 Diallyl-phthalate Substances 0.000 description 2
- VZCYOOQTPOCHFL-OWOJBTEDSA-N Fumaric acid Chemical compound OC(=O)\C=C\C(O)=O VZCYOOQTPOCHFL-OWOJBTEDSA-N 0.000 description 2
- 239000005057 Hexamethylene diisocyanate Substances 0.000 description 2
- OFBQJSOFQDEBGM-UHFFFAOYSA-N Pentane Chemical compound CCCCC OFBQJSOFQDEBGM-UHFFFAOYSA-N 0.000 description 2
- CZMRCDWAGMRECN-UGDNZRGBSA-N Sucrose Chemical compound O[C@H]1[C@H](O)[C@@H](CO)O[C@@]1(CO)O[C@@H]1[C@H](O)[C@@H](O)[C@H](O)[C@@H](CO)O1 CZMRCDWAGMRECN-UGDNZRGBSA-N 0.000 description 2
- LWZFANDGMFTDAV-BURFUSLBSA-N [(2r)-2-[(2r,3r,4s)-3,4-dihydroxyoxolan-2-yl]-2-hydroxyethyl] dodecanoate Chemical compound CCCCCCCCCCCC(=O)OC[C@@H](O)[C@H]1OC[C@H](O)[C@H]1O LWZFANDGMFTDAV-BURFUSLBSA-N 0.000 description 2
- 150000001252 acrylic acid derivatives Chemical class 0.000 description 2
- 150000001338 aliphatic hydrocarbons Chemical class 0.000 description 2
- ROOXNKNUYICQNP-UHFFFAOYSA-N ammonium persulfate Chemical compound [NH4+].[NH4+].[O-]S(=O)(=O)OOS([O-])(=O)=O ROOXNKNUYICQNP-UHFFFAOYSA-N 0.000 description 2
- 150000004945 aromatic hydrocarbons Chemical class 0.000 description 2
- QUDWYFHPNIMBFC-UHFFFAOYSA-N bis(prop-2-enyl) benzene-1,2-dicarboxylate Chemical compound C=CCOC(=O)C1=CC=CC=C1C(=O)OCC=C QUDWYFHPNIMBFC-UHFFFAOYSA-N 0.000 description 2
- 230000003750 conditioning effect Effects 0.000 description 2
- 238000010528 free radical solution polymerization reaction Methods 0.000 description 2
- 125000000524 functional group Chemical group 0.000 description 2
- 235000011187 glycerol Nutrition 0.000 description 2
- 229920000578 graft copolymer Polymers 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- RRAMGCGOFNQTLD-UHFFFAOYSA-N hexamethylene diisocyanate Chemical compound O=C=NCCCCCCN=C=O RRAMGCGOFNQTLD-UHFFFAOYSA-N 0.000 description 2
- 229930195733 hydrocarbon Natural products 0.000 description 2
- 150000002430 hydrocarbons Chemical class 0.000 description 2
- WGCNASOHLSPBMP-UHFFFAOYSA-N hydroxyacetaldehyde Natural products OCC=O WGCNASOHLSPBMP-UHFFFAOYSA-N 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- UAEPNZWRGJTJPN-UHFFFAOYSA-N methylcyclohexane Chemical compound CC1CCCCC1 UAEPNZWRGJTJPN-UHFFFAOYSA-N 0.000 description 2
- GDOPTJXRTPNYNR-UHFFFAOYSA-N methylcyclopentane Chemical compound CC1CCCC1 GDOPTJXRTPNYNR-UHFFFAOYSA-N 0.000 description 2
- 229910052757 nitrogen Inorganic materials 0.000 description 2
- 229920000642 polymer Polymers 0.000 description 2
- 229920005862 polyol Polymers 0.000 description 2
- 150000003077 polyols Chemical class 0.000 description 2
- 238000010992 reflux Methods 0.000 description 2
- 239000002689 soil Substances 0.000 description 2
- 229940035044 sorbitan monolaurate Drugs 0.000 description 2
- 239000000725 suspension Substances 0.000 description 2
- DVKJHBMWWAPEIU-UHFFFAOYSA-N toluene 2,4-diisocyanate Chemical compound CC1=CC=C(N=C=O)C=C1N=C=O DVKJHBMWWAPEIU-UHFFFAOYSA-N 0.000 description 2
- LCPVQAHEFVXVKT-UHFFFAOYSA-N 2-(2,4-difluorophenoxy)pyridin-3-amine Chemical compound NC1=CC=CN=C1OC1=CC=C(F)C=C1F LCPVQAHEFVXVKT-UHFFFAOYSA-N 0.000 description 1
- JJBFVQSGPLGDNX-UHFFFAOYSA-N 2-(2-methylprop-2-enoyloxy)propyl 2-methylprop-2-enoate Chemical compound CC(=C)C(=O)OC(C)COC(=O)C(C)=C JJBFVQSGPLGDNX-UHFFFAOYSA-N 0.000 description 1
- 125000000954 2-hydroxyethyl group Chemical group [H]C([*])([H])C([H])([H])O[H] 0.000 description 1
- AUZRCMMVHXRSGT-UHFFFAOYSA-N 2-methylpropane-1-sulfonic acid;prop-2-enamide Chemical compound NC(=O)C=C.CC(C)CS(O)(=O)=O AUZRCMMVHXRSGT-UHFFFAOYSA-N 0.000 description 1
- VFZKVQVQOMDJEG-UHFFFAOYSA-N 2-prop-2-enoyloxypropyl prop-2-enoate Chemical compound C=CC(=O)OC(C)COC(=O)C=C VFZKVQVQOMDJEG-UHFFFAOYSA-N 0.000 description 1
- 239000004342 Benzoyl peroxide Substances 0.000 description 1
- OMPJBNCRMGITSC-UHFFFAOYSA-N Benzoylperoxide Chemical compound C=1C=CC=CC=1C(=O)OOC(=O)C1=CC=CC=C1 OMPJBNCRMGITSC-UHFFFAOYSA-N 0.000 description 1
- GAWIXWVDTYZWAW-UHFFFAOYSA-N C[CH]O Chemical group C[CH]O GAWIXWVDTYZWAW-UHFFFAOYSA-N 0.000 description 1
- BRLQWZUYTZBJKN-UHFFFAOYSA-N Epichlorohydrin Chemical compound ClCC1CO1 BRLQWZUYTZBJKN-UHFFFAOYSA-N 0.000 description 1
- 229920002125 Sokalan® Polymers 0.000 description 1
- 229920002472 Starch Polymers 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 1
- LSNNMFCWUKXFEE-UHFFFAOYSA-N Sulfurous acid Chemical compound OS(O)=O LSNNMFCWUKXFEE-UHFFFAOYSA-N 0.000 description 1
- ZJCCRDAZUWHFQH-UHFFFAOYSA-N Trimethylolpropane Chemical compound CCC(CO)(CO)CO ZJCCRDAZUWHFQH-UHFFFAOYSA-N 0.000 description 1
- 150000007513 acids Chemical class 0.000 description 1
- 150000005215 alkyl ethers Chemical class 0.000 description 1
- 125000000217 alkyl group Chemical group 0.000 description 1
- 125000005037 alkyl phenyl group Chemical group 0.000 description 1
- 125000003277 amino group Chemical group 0.000 description 1
- 229910001870 ammonium persulfate Inorganic materials 0.000 description 1
- 235000019400 benzoyl peroxide Nutrition 0.000 description 1
- 239000001913 cellulose Substances 0.000 description 1
- 229920002678 cellulose Polymers 0.000 description 1
- 239000011362 coarse particle Substances 0.000 description 1
- 229920001577 copolymer Polymers 0.000 description 1
- 238000004132 cross linking Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- GKIPXFAANLTWBM-UHFFFAOYSA-N epibromohydrin Chemical compound BrCC1CO1 GKIPXFAANLTWBM-UHFFFAOYSA-N 0.000 description 1
- CYKDLUMZOVATFT-UHFFFAOYSA-N ethenyl acetate;prop-2-enoic acid Chemical compound OC(=O)C=C.CC(=O)OC=C CYKDLUMZOVATFT-UHFFFAOYSA-N 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 239000000706 filtrate Substances 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 235000013305 food Nutrition 0.000 description 1
- 239000001530 fumaric acid Substances 0.000 description 1
- 238000000227 grinding Methods 0.000 description 1
- DMEGYFMYUHOHGS-UHFFFAOYSA-N heptamethylene Natural products C1CCCCCC1 DMEGYFMYUHOHGS-UHFFFAOYSA-N 0.000 description 1
- 239000003999 initiator Substances 0.000 description 1
- 150000002513 isocyanates Chemical class 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 230000002175 menstrual effect Effects 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 125000005641 methacryl group Chemical group 0.000 description 1
- GYNNXHKOJHMOHS-UHFFFAOYSA-N methyl-cycloheptane Natural products CC1CCCCCC1 GYNNXHKOJHMOHS-UHFFFAOYSA-N 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 239000004584 polyacrylic acid Substances 0.000 description 1
- 229920000647 polyepoxide Polymers 0.000 description 1
- 239000005056 polyisocyanate Substances 0.000 description 1
- 229920001228 polyisocyanate Polymers 0.000 description 1
- 239000003505 polymerization initiator Substances 0.000 description 1
- 229920001451 polypropylene glycol Polymers 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 239000012966 redox initiator Substances 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 239000012047 saturated solution Substances 0.000 description 1
- CHQMHPLRPQMAMX-UHFFFAOYSA-L sodium persulfate Substances [Na+].[Na+].[O-]S(=O)(=O)OOS([O-])(=O)=O CHQMHPLRPQMAMX-UHFFFAOYSA-L 0.000 description 1
- 239000012798 spherical particle Substances 0.000 description 1
- 239000008107 starch Substances 0.000 description 1
- 235000019698 starch Nutrition 0.000 description 1
- 239000002344 surface layer Substances 0.000 description 1
- 238000010558 suspension polymerization method Methods 0.000 description 1
- 229920006305 unsaturated polyester Polymers 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F20/00—Homopolymers and copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride, ester, amide, imide or nitrile thereof
- C08F20/02—Monocarboxylic acids having less than ten carbon atoms, Derivatives thereof
- C08F20/04—Acids, Metal salts or ammonium salts thereof
- C08F20/06—Acrylic acid; Methacrylic acid; Metal salts or ammonium salts thereof
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F2/00—Processes of polymerisation
- C08F2/32—Polymerisation in water-in-oil emulsions
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61L—METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
- A61L15/00—Chemical aspects of, or use of materials for, bandages, dressings or absorbent pads
- A61L15/16—Bandages, dressings or absorbent pads for physiological fluids such as urine or blood, e.g. sanitary towels, tampons
- A61L15/42—Use of materials characterised by their function or physical properties
- A61L15/60—Liquid-swellable gel-forming materials, e.g. super-absorbents
Landscapes
- Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- Organic Chemistry (AREA)
- Polymers & Plastics (AREA)
- Medicinal Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Animal Behavior & Ethology (AREA)
- Life Sciences & Earth Sciences (AREA)
- Epidemiology (AREA)
- General Health & Medical Sciences (AREA)
- Public Health (AREA)
- Veterinary Medicine (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Materials Engineering (AREA)
- Engineering & Computer Science (AREA)
- Hematology (AREA)
- Dispersion Chemistry (AREA)
- Polymerisation Methods In General (AREA)
- Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)
Abstract
The present invention is directed to an improved process for the production of a water-absorbent resin by reversed phase suspension polymerization of a water-soluble ethylenic unsaturated monomer. The process is conducted by subjecting an aqueous solution of a water-soluble ethylenic unsaturated monomer to a reversed phase suspension polymerization reaction in a first stage. The polymerization is conducted in a petroleum hydrocarbon solvent in the presence of a surfactant and/or polymeric protective colloid using a radical polymerization initiator optionally in the presence of a crosslinking agent, cooling the resulting slurry to precipitate the surfactant and/or polymeric protective colloid, and then repeating the polymerization by adding an aqueous solution of a water-soluble ethylenic unsaturated monomer containing a radical polymerization initiator and optionally a crosslinking agent to the first polymerization reaction system to further carry out the reversed phase suspension polymerization reaction, at least, once.
Description
'~ 1 2034~93 PROCESS FOR PRODUCTION OF WATER-ABSORBENT RESIN
The present invention relates to the production of a water-absorbent resin. More particularly, it relates to a process for the production of a water-absorbent resin having properties suitable for water-absorbent materials in the sanitary material field. The water-absorbent resin is inexpensively prepared and has a very large number of uses.
Recently, water-absorbent resins have been used in the sanitary product field, e.g. menstrual articles, diapers and the like, in the agricultural and horticultural fields, e.g. water retention agents, soil conditioning agents and the like and in industrial fields, e.g. cutoff materials, antidewing agents and the like, and they are useful in various applications. Among the various uses, water-absorbent resins are prosperously used in the sanitary product field.
These water-absorbent resins are polymers which are lightly crosslinked, and examples thereof include hydrolyzates of starch-acrylonitrile graft copolymer (Japanese Patent Kokoku No. 49-43395), neutralized products of starch-acrylic acid graft copolymer (Japanese Patent Kokai No. 51-125468), saponified products of vinyl acetate-acrylic acid ester copolymer (Japanese Patent Kokai No. 52-14689), partially neutralized polyacrylic acid products (Japanese Patent Kokai Nos. 62-172006, 57-158209 and 57-21405) and the like.
~ 2 2n34293 The usual desirable properties of water-absorbent resins are high absorbency, excellent water-absorption rate, high gel strength after absorption of water, shape suitable for application, conformability to materials with which the resins will be used and the like. In particular, the desired properties for water-absorbent resins used in sanitary products are high absorbency, high water-absorption rate, high gel strength after absorption of water, large particle size, less fine powder, a sharp particle size distribution, integrity with a pulp, a small amount of reversion of absorbed substances to the exterior of the product, excellent diffusion of absorbed substances into the interior of the absorbents and the like. It can be said that a good water-absorbent material should satisfy these properties as well as be safe and cheap.
Thus, hitherto, water-absorbent resins have been mainly produced by solution polymerization or reversed phase suspension polymerization of water-soluble ethylenic unsaturated monomers. The production of water-absorbent resins by reversed phase suspension polymerization has the following disadvantages.
Firstly, a water-absorbent resin obtained by reversed phase suspension polymerization method of a water-20~29~
_ 3 soluble ethylenic unsaturated monomer is a powder of sphericalparticles having a sharp particle size distribution in comparison with that obtained by subjecting the monomer to solution polymerization, followed by grinding. However, large particle size water-absorbent resins cannot be obtained.
Secondly, since a surfactant and/or a polymeric protective colloid are used, they remain on the surface of the product obtained and therefore initial water wettability is inferior as water is repelled by the surfactant and/or polymeric protective colloid. As means to mitigate this phenomenon and to improve the initial water wettability, it has been considered to remove the surfactant and/or polymeric protective colloid from the product by filtering a slurry obtained by reversed phase suspension polymerization and drying. However, purification of the filtrate is very expensive and such a process is far from economical, although initial water wettability is improved. Thirdly, polymerization of a water-soluble ethylenic unsaturated monomer is an exothermic reaction and heat is generated over a short period of time. Therefore, in the reversed phase suspension polymerization, increase in the amount of the monomer in the solvent is limited due to removal of heat.
Accordingly, productivity improvement by decreasing the solvent and increasing the amount of monomer is limited.
Fourthly, in the reversed phase suspension polymerization, the surfactant and/or polymeric protective colloid should be used, at least, in an amount sufficient to make a suspension in order to carry out a stable polymerization, and the amount cannot be reduced to less than this required minimum amount.
In order to solve the above problems, the present inventors have studied intensively. As a result, it has been found that, by carrying out the reversed phase suspension polymerization in multiple stages, a water-absorbent resin having large particle size, less fine powder, a sharp distribution and very good water wettability in addition to very good water absorption properties can be obtained, productivity can be highly improved and further the amount of surfactant and/or polymeric protective colloid used can be reduced.
The main object of the present invention is to provide an improved process for the production of a water-absorbent resin by reversed phase suspension polymerization of a water-soluble ethylenic unsaturated monomer.
This object as well as other objects and advantages of the present invention will be apparent to those skilled in the art from the following description.
s According to the present invention, there is provided a process for the production of a water-absorbent resin by reversed phase suspension polymerization of a water-soluble ethylenic unsaturated monomer comprising, in a first stage, subjecting an aqueous solution of a water-soluble ethylenic unsaturated monomer to reversed phase suspension polymerization reaction in a petroleum hydrocarbon solvent in the presence of a surfactant and/or polymeric protective colloid using a radical polymerization initiator optionally in the presence of a crosslinking agent, cooling the resulting slurry to precipitate the surfactant and/or polymeric protective colloid, and repeating the polymerization by adding an aqueous solution of a water-soluble ethylenic unsaturated monomer containing a radical polymerization initiator and optionally a crosslinking agent to the first polymerization reaction system to further carry out the reversed phase suspension polymerization reaction, at least, once.
In the process of the present invention, the reversed phase suspension polymerization reaction is carried out in multiple stages of, at least, two stages.
Since, the desired result can usually be obtained by a two stage polymerization reaction, the two stage 20342g3 reaction is explained below.
That is, according to the process of the present invention, to carry out the two stage reaction, an aqueous solution of a water-soluble ethylenic unsaturated S monomer is firstly polymerized in a petroleum hydrocarbon solvent in the presence of a surfactant and/or polymeric protective colloid using a radical polymerization initiator optionally in the presence of a crosslinking agent. Then, after polymerization, the resulting slurry solution is cooled so that the surfactant and/or polymeric protective colloid precipitate in the solvent to prevent a suspension of an aqueous solution of a monomer for the second stage. Then, the monomer solution of the second stage is added and absorbed to a water-containing gel produced by the first polymerization and the second polymerization is carried out.
When the monomer solution of the second stage is added to the reaction system under conditions where the surfactant and/or polymeric protective colloid are dissolved in the solvent after the completion of the first polymerization, the monomer solution is suspended before it is absorbed to the water-containing gel obtained by the first polymerization and, therefore, the particle size of the resulting product is small and the distribution thereof is broad. When the monomer solution of the second stage is added to the reaction system under eonditions where the surfactant and/or polymeric protective colloid are precipitated in the solvent, the water-containing gel obtained by the first polymerization is hardly effected by surface activities of the surfactant and/or polymeric protective colloid and, therefore, a water-absorbent resin having large particle size, less fine powder and a sharp particle size distribution can be obtained.
Further, water wettability of the resulting water-absorbent resin is remarkably improved. Perhaps, this results from the enYelopment of the surfactant and/or polymeric protective colloid with the monomer solution of the second stage upon absorption of the solution to the water-containing gel obtained by the first polymerization.
The water-soluble ethylenic unsaturated monomer used may be any of the conventional monomers. Examples thereof include (meth)acrylic acid, 2-(meth)acrylamide-2 methylpropanesulfonic acid and/or alkali salts thereof, nonionic monomers, e.~g. (meth)acrylamide, N,N-dimethyl acrylamide, 2-hydroxyethyl(meth)acrylate, N-methylol(meth)acrylamide and the like, amino group-containing unsaturated monomers, e.g. diethylaminoethyl-(meth)acrylate, diethylaminopropyl(meth)acrylate, dimethylaminopropyl(meth)acrylate and the like, and quaternized products thereof. They are used alone or in combinations thereof. (The term "(meth)acryl" used herein means both "acryl" and "methacryl".) Among them, acrylic '._ , acid, methacrylic acid or alkali salts thereof, acrylamide, methacrylamide, N,N-dimethylacrylamide are preferred.
Further, the monomer component used in the second and subsequent stages may be the same as or different from that used in the first stage. In general, the monomer concentration in the aqueous solution of a water-soluble ethylenic unsaturated monomer is preferably 25% by weight to its saturated solution.
Any surfactant and polymeric protective colloid can be used in so far as the reversed phase suspension polymerization can proceed in the first stage polymeri-zation, and they can be used in combination thereof.
As the surfactant, for example, there can be used nonionic surfactants, e.g. sorbitan fatty acid ester, polyglycerin fatty acid ester, sucrose fatty acid ester, sorbitol fatty acid ester, polyoxyethylene alkylphenyl ether and the like. As the polymeric protective colloid, for example, there can be used ethyl cellulose, ethyl hydroxyethyl cellulose, oxidized polyethylene, polyethylene modified with maleic anhydride, EPDM (ethylene-propylene-diene-terpolymer) modified with maleic anhydride and the like. Further, anionic surfactants, e.g. fatty acid salts, alkyl benzenesulfonate salts, alkyl methyltaurate salts, polyoxyethylene alkylphenyl ether sulfate, polyoxyethylene alkyl ether sulfonate and the like can also be used in combination with the nonionic surfactants and/or polymeric ~,, .~
protective colloid.
The amount of these surfactants and/or polymeric protective colloids used is 0.1 to 5~ by weight, preferably, 0.2 to 3~ by weight based on the total weight of the aqueous monomer solution of the first stage.
The petroleum hydrocarbon solvent used is, for exan~le, an aliphatic hydrocarbon, a cycloaliphatic hydrocarbon or an aromatic hydrocarbon. As ~ aliphatic hydrocarbon, n-pentane, n-hexane, n-heptane, ligroin and the like are preferred. As the cycloaliphatic hydrocarbon, cyclopentane, methylcyclopentane, cyclohexane, methylcyclohexane, and the like are preferred. As the aromatic hydrocarbon, benzene, toluene, xylene and the like are preferred. Particularly, n-hexane, n-heptane, cyclohexane, toluene and xylene can be advantageously used because they are easily available and cheap in addition to their stable industrial qualities.
The crosslinking agent optionally used in the first stage and the second and subsequent stages is one having at least two polymerizable unsaturated groups and/or reactive functional groups. Examples of the crosslinking agent having at least two polymerizable unsaturated groups include di- or tri(meth)acrylate esters of polyols? e.g. ethylene glycol, propylene glycol, trimethylolpropane, glycerin polyoxyethylene glycol, polyoxypropylene glycol, polyglycerin and the like, unsaturated polyesters obtained lo 20~429~
by reacting the above polyols with unsaturated acids, e.g.
maleic acid, fumaric acid and the like, bisacrylamides, e.g.
N,N'-methylene bisacrylamide and the like, di- or tri(meth)acrylate esters obtained by reacting polyepoxide with (meth)acrylic acid, di(meth)acrylate carbamyl esters obtained by reacting polyisocyanates, e.g. tolylene diisocyanate, hexamethylene diisocyanate and the like with hydroxyethyl (meth)acrylate, allylated starch, allylated cellulose, diallyl phthalate, N,N',N"-triallyl isocyanurate, divinylbenzene and the like.
Among them, ethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate, diethylene glycol dimethacrylate, propylene glycol diacrylate, propylene glycol dimethacrylate, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, diallyl phthalate, N,N',N"-triallyl isocyanate, N,N'-methylene bisacrylamide and the like are usually used.
The crosslinking agent having at least two reactive functional groups is, for example, diglycidyl ether compounds, haloepoxy compounds, isocyanate compounds and the like. Among them, particularly, the diglycidyl ether compound is suitable. Examples of the diglycidyl ether include (poly)ethylene glycol diglycidyl ether, (poly)propylene glycol glycidyl ether, (poly)glycerin glycidyl ether and the like. Among them, ethylene glycol diglycidyl ether provides the most preferred results. (The term 203~293 ._ "(poly)ethylene glycol" used herein means both "ethylene glycol" and "polyethylene glycol"). Further, examples of the haloepoxy compound include epichlorohydrin, epibromohydrin, ~-methylepichlorohydrin and the like and examples of the isocyanate compound include 2,4-tolylene diisocyanate, hexamethylene diisocyanate and the like. Any of these compounds can be used in the present invention. In general, the crosslinking agent is used in an amount of 0.001 to 5% by weight based on the weight of the monomer.
As the radical polymerization initiator used, conventional water-soluble radical polymerization initiators ?
e~ g. potassium persulfate, ammonium persulfate, sodium persulfate and the like are suitable and these can be used in combination with sulfite and the like as a redox initiator. However, in the case of using an oil-soluble radical polymerization initiator, since the resulting polymer generally becomes water-soluble, it should be used in the presence of the crosslinking agent. In this case, oil-soluble initiators, e . g . benzoyl peroxide, azobisisobutyronitrile and the like are suitable. It is preferred to use the radical polymerization initiator in an amount ranging from 0.005 to 1.0 mol% based on the monomer. When the amount is less than 0.005 mol~, it takes a very long time to carry out the polymerization reaction and, when the amount exceeds 1.0 mol%, a rapid polymerization reaction occurs. Such a reaction is dangerous.
203~293 The polymerization temperature varies depending upon the polymerization initiator to be used. The polymerization temperature is usually 20 to 110~C, preferably, 40 to 80~C. When the polymerization is carried out at a temperature higher than 110~C, it is difficult to remove the polymerization heat and, therefore, the polymerization cannot be ca~ried out smoathly. -When the polymerization is carried out at a temperature lower than 20~C, the polymerization rate is lowered and a long polymerization time is required. This is not preferred from an economical viewpoint.
Precipitation of the surfactant and/or polymeric protective colloid after the first stage polymerization, which is one of the characteristics of the present invention, is carried out by cooling the reaction system.
The cooling temperature varies depending upon the surfactant and polymeric protective colloid used as well as the type of solvent. For example, in the case of hexaglyceryl monobehenylate and n-heptane, the temperature is 38 to 40~C. In the case of hexaglyceryl monobehenylate and cyclohexane, the temperature is 27 to 30~C and, in the case of sorbitan monostearate and n-heptane, the temperature is 29 to 31~C.
The amount of the aqueous solution of the water-soluble ethylenic monomer containing the radical polymerization initiator and optionally the crosslinking '- 2034293 agent used in the second and subsequent stages, which is absorbed to the water-containing gel obtained by the first stage polymerization, is 50 ~o 300~ by weight based on the total weight of the a~ueous water-soluble ethylenic unsaturated monomer solution of the first stage.
When the amount of the aqueous solution of the water-soluble ethylenic unsaturated monomer of the second and subsequent stages is less than 50% by weight, the various desired advantages of the present invention can hardly be expected. On the other hand, when the amount is more than 300% by weight, the monomer solution is not completely absorbed during absorption of the second and subsequent stages. This is undesirable because it forms a mass or extremely large coarse particles.
The following Examples further illustrate the present invention in detail but are not to be construed to limit the scope thereof.
In each Example, physical properties of the water-absorbent resin were determined according to the following methods.
(l) Absorbency A water-absorbent resin (l g) was dispersed in a 0.9% (w/w) aqueous solution of sodium chloride t200 ml), thoroughly swollen and then filtered through a 200 mesh metal wire net. The resulting swollen resin was weighed and the weight was taken as the absorbency.
~.
The present invention relates to the production of a water-absorbent resin. More particularly, it relates to a process for the production of a water-absorbent resin having properties suitable for water-absorbent materials in the sanitary material field. The water-absorbent resin is inexpensively prepared and has a very large number of uses.
Recently, water-absorbent resins have been used in the sanitary product field, e.g. menstrual articles, diapers and the like, in the agricultural and horticultural fields, e.g. water retention agents, soil conditioning agents and the like and in industrial fields, e.g. cutoff materials, antidewing agents and the like, and they are useful in various applications. Among the various uses, water-absorbent resins are prosperously used in the sanitary product field.
These water-absorbent resins are polymers which are lightly crosslinked, and examples thereof include hydrolyzates of starch-acrylonitrile graft copolymer (Japanese Patent Kokoku No. 49-43395), neutralized products of starch-acrylic acid graft copolymer (Japanese Patent Kokai No. 51-125468), saponified products of vinyl acetate-acrylic acid ester copolymer (Japanese Patent Kokai No. 52-14689), partially neutralized polyacrylic acid products (Japanese Patent Kokai Nos. 62-172006, 57-158209 and 57-21405) and the like.
~ 2 2n34293 The usual desirable properties of water-absorbent resins are high absorbency, excellent water-absorption rate, high gel strength after absorption of water, shape suitable for application, conformability to materials with which the resins will be used and the like. In particular, the desired properties for water-absorbent resins used in sanitary products are high absorbency, high water-absorption rate, high gel strength after absorption of water, large particle size, less fine powder, a sharp particle size distribution, integrity with a pulp, a small amount of reversion of absorbed substances to the exterior of the product, excellent diffusion of absorbed substances into the interior of the absorbents and the like. It can be said that a good water-absorbent material should satisfy these properties as well as be safe and cheap.
Thus, hitherto, water-absorbent resins have been mainly produced by solution polymerization or reversed phase suspension polymerization of water-soluble ethylenic unsaturated monomers. The production of water-absorbent resins by reversed phase suspension polymerization has the following disadvantages.
Firstly, a water-absorbent resin obtained by reversed phase suspension polymerization method of a water-20~29~
_ 3 soluble ethylenic unsaturated monomer is a powder of sphericalparticles having a sharp particle size distribution in comparison with that obtained by subjecting the monomer to solution polymerization, followed by grinding. However, large particle size water-absorbent resins cannot be obtained.
Secondly, since a surfactant and/or a polymeric protective colloid are used, they remain on the surface of the product obtained and therefore initial water wettability is inferior as water is repelled by the surfactant and/or polymeric protective colloid. As means to mitigate this phenomenon and to improve the initial water wettability, it has been considered to remove the surfactant and/or polymeric protective colloid from the product by filtering a slurry obtained by reversed phase suspension polymerization and drying. However, purification of the filtrate is very expensive and such a process is far from economical, although initial water wettability is improved. Thirdly, polymerization of a water-soluble ethylenic unsaturated monomer is an exothermic reaction and heat is generated over a short period of time. Therefore, in the reversed phase suspension polymerization, increase in the amount of the monomer in the solvent is limited due to removal of heat.
Accordingly, productivity improvement by decreasing the solvent and increasing the amount of monomer is limited.
Fourthly, in the reversed phase suspension polymerization, the surfactant and/or polymeric protective colloid should be used, at least, in an amount sufficient to make a suspension in order to carry out a stable polymerization, and the amount cannot be reduced to less than this required minimum amount.
In order to solve the above problems, the present inventors have studied intensively. As a result, it has been found that, by carrying out the reversed phase suspension polymerization in multiple stages, a water-absorbent resin having large particle size, less fine powder, a sharp distribution and very good water wettability in addition to very good water absorption properties can be obtained, productivity can be highly improved and further the amount of surfactant and/or polymeric protective colloid used can be reduced.
The main object of the present invention is to provide an improved process for the production of a water-absorbent resin by reversed phase suspension polymerization of a water-soluble ethylenic unsaturated monomer.
This object as well as other objects and advantages of the present invention will be apparent to those skilled in the art from the following description.
s According to the present invention, there is provided a process for the production of a water-absorbent resin by reversed phase suspension polymerization of a water-soluble ethylenic unsaturated monomer comprising, in a first stage, subjecting an aqueous solution of a water-soluble ethylenic unsaturated monomer to reversed phase suspension polymerization reaction in a petroleum hydrocarbon solvent in the presence of a surfactant and/or polymeric protective colloid using a radical polymerization initiator optionally in the presence of a crosslinking agent, cooling the resulting slurry to precipitate the surfactant and/or polymeric protective colloid, and repeating the polymerization by adding an aqueous solution of a water-soluble ethylenic unsaturated monomer containing a radical polymerization initiator and optionally a crosslinking agent to the first polymerization reaction system to further carry out the reversed phase suspension polymerization reaction, at least, once.
In the process of the present invention, the reversed phase suspension polymerization reaction is carried out in multiple stages of, at least, two stages.
Since, the desired result can usually be obtained by a two stage polymerization reaction, the two stage 20342g3 reaction is explained below.
That is, according to the process of the present invention, to carry out the two stage reaction, an aqueous solution of a water-soluble ethylenic unsaturated S monomer is firstly polymerized in a petroleum hydrocarbon solvent in the presence of a surfactant and/or polymeric protective colloid using a radical polymerization initiator optionally in the presence of a crosslinking agent. Then, after polymerization, the resulting slurry solution is cooled so that the surfactant and/or polymeric protective colloid precipitate in the solvent to prevent a suspension of an aqueous solution of a monomer for the second stage. Then, the monomer solution of the second stage is added and absorbed to a water-containing gel produced by the first polymerization and the second polymerization is carried out.
When the monomer solution of the second stage is added to the reaction system under conditions where the surfactant and/or polymeric protective colloid are dissolved in the solvent after the completion of the first polymerization, the monomer solution is suspended before it is absorbed to the water-containing gel obtained by the first polymerization and, therefore, the particle size of the resulting product is small and the distribution thereof is broad. When the monomer solution of the second stage is added to the reaction system under eonditions where the surfactant and/or polymeric protective colloid are precipitated in the solvent, the water-containing gel obtained by the first polymerization is hardly effected by surface activities of the surfactant and/or polymeric protective colloid and, therefore, a water-absorbent resin having large particle size, less fine powder and a sharp particle size distribution can be obtained.
Further, water wettability of the resulting water-absorbent resin is remarkably improved. Perhaps, this results from the enYelopment of the surfactant and/or polymeric protective colloid with the monomer solution of the second stage upon absorption of the solution to the water-containing gel obtained by the first polymerization.
The water-soluble ethylenic unsaturated monomer used may be any of the conventional monomers. Examples thereof include (meth)acrylic acid, 2-(meth)acrylamide-2 methylpropanesulfonic acid and/or alkali salts thereof, nonionic monomers, e.~g. (meth)acrylamide, N,N-dimethyl acrylamide, 2-hydroxyethyl(meth)acrylate, N-methylol(meth)acrylamide and the like, amino group-containing unsaturated monomers, e.g. diethylaminoethyl-(meth)acrylate, diethylaminopropyl(meth)acrylate, dimethylaminopropyl(meth)acrylate and the like, and quaternized products thereof. They are used alone or in combinations thereof. (The term "(meth)acryl" used herein means both "acryl" and "methacryl".) Among them, acrylic '._ , acid, methacrylic acid or alkali salts thereof, acrylamide, methacrylamide, N,N-dimethylacrylamide are preferred.
Further, the monomer component used in the second and subsequent stages may be the same as or different from that used in the first stage. In general, the monomer concentration in the aqueous solution of a water-soluble ethylenic unsaturated monomer is preferably 25% by weight to its saturated solution.
Any surfactant and polymeric protective colloid can be used in so far as the reversed phase suspension polymerization can proceed in the first stage polymeri-zation, and they can be used in combination thereof.
As the surfactant, for example, there can be used nonionic surfactants, e.g. sorbitan fatty acid ester, polyglycerin fatty acid ester, sucrose fatty acid ester, sorbitol fatty acid ester, polyoxyethylene alkylphenyl ether and the like. As the polymeric protective colloid, for example, there can be used ethyl cellulose, ethyl hydroxyethyl cellulose, oxidized polyethylene, polyethylene modified with maleic anhydride, EPDM (ethylene-propylene-diene-terpolymer) modified with maleic anhydride and the like. Further, anionic surfactants, e.g. fatty acid salts, alkyl benzenesulfonate salts, alkyl methyltaurate salts, polyoxyethylene alkylphenyl ether sulfate, polyoxyethylene alkyl ether sulfonate and the like can also be used in combination with the nonionic surfactants and/or polymeric ~,, .~
protective colloid.
The amount of these surfactants and/or polymeric protective colloids used is 0.1 to 5~ by weight, preferably, 0.2 to 3~ by weight based on the total weight of the aqueous monomer solution of the first stage.
The petroleum hydrocarbon solvent used is, for exan~le, an aliphatic hydrocarbon, a cycloaliphatic hydrocarbon or an aromatic hydrocarbon. As ~ aliphatic hydrocarbon, n-pentane, n-hexane, n-heptane, ligroin and the like are preferred. As the cycloaliphatic hydrocarbon, cyclopentane, methylcyclopentane, cyclohexane, methylcyclohexane, and the like are preferred. As the aromatic hydrocarbon, benzene, toluene, xylene and the like are preferred. Particularly, n-hexane, n-heptane, cyclohexane, toluene and xylene can be advantageously used because they are easily available and cheap in addition to their stable industrial qualities.
The crosslinking agent optionally used in the first stage and the second and subsequent stages is one having at least two polymerizable unsaturated groups and/or reactive functional groups. Examples of the crosslinking agent having at least two polymerizable unsaturated groups include di- or tri(meth)acrylate esters of polyols? e.g. ethylene glycol, propylene glycol, trimethylolpropane, glycerin polyoxyethylene glycol, polyoxypropylene glycol, polyglycerin and the like, unsaturated polyesters obtained lo 20~429~
by reacting the above polyols with unsaturated acids, e.g.
maleic acid, fumaric acid and the like, bisacrylamides, e.g.
N,N'-methylene bisacrylamide and the like, di- or tri(meth)acrylate esters obtained by reacting polyepoxide with (meth)acrylic acid, di(meth)acrylate carbamyl esters obtained by reacting polyisocyanates, e.g. tolylene diisocyanate, hexamethylene diisocyanate and the like with hydroxyethyl (meth)acrylate, allylated starch, allylated cellulose, diallyl phthalate, N,N',N"-triallyl isocyanurate, divinylbenzene and the like.
Among them, ethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate, diethylene glycol dimethacrylate, propylene glycol diacrylate, propylene glycol dimethacrylate, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, diallyl phthalate, N,N',N"-triallyl isocyanate, N,N'-methylene bisacrylamide and the like are usually used.
The crosslinking agent having at least two reactive functional groups is, for example, diglycidyl ether compounds, haloepoxy compounds, isocyanate compounds and the like. Among them, particularly, the diglycidyl ether compound is suitable. Examples of the diglycidyl ether include (poly)ethylene glycol diglycidyl ether, (poly)propylene glycol glycidyl ether, (poly)glycerin glycidyl ether and the like. Among them, ethylene glycol diglycidyl ether provides the most preferred results. (The term 203~293 ._ "(poly)ethylene glycol" used herein means both "ethylene glycol" and "polyethylene glycol"). Further, examples of the haloepoxy compound include epichlorohydrin, epibromohydrin, ~-methylepichlorohydrin and the like and examples of the isocyanate compound include 2,4-tolylene diisocyanate, hexamethylene diisocyanate and the like. Any of these compounds can be used in the present invention. In general, the crosslinking agent is used in an amount of 0.001 to 5% by weight based on the weight of the monomer.
As the radical polymerization initiator used, conventional water-soluble radical polymerization initiators ?
e~ g. potassium persulfate, ammonium persulfate, sodium persulfate and the like are suitable and these can be used in combination with sulfite and the like as a redox initiator. However, in the case of using an oil-soluble radical polymerization initiator, since the resulting polymer generally becomes water-soluble, it should be used in the presence of the crosslinking agent. In this case, oil-soluble initiators, e . g . benzoyl peroxide, azobisisobutyronitrile and the like are suitable. It is preferred to use the radical polymerization initiator in an amount ranging from 0.005 to 1.0 mol% based on the monomer. When the amount is less than 0.005 mol~, it takes a very long time to carry out the polymerization reaction and, when the amount exceeds 1.0 mol%, a rapid polymerization reaction occurs. Such a reaction is dangerous.
203~293 The polymerization temperature varies depending upon the polymerization initiator to be used. The polymerization temperature is usually 20 to 110~C, preferably, 40 to 80~C. When the polymerization is carried out at a temperature higher than 110~C, it is difficult to remove the polymerization heat and, therefore, the polymerization cannot be ca~ried out smoathly. -When the polymerization is carried out at a temperature lower than 20~C, the polymerization rate is lowered and a long polymerization time is required. This is not preferred from an economical viewpoint.
Precipitation of the surfactant and/or polymeric protective colloid after the first stage polymerization, which is one of the characteristics of the present invention, is carried out by cooling the reaction system.
The cooling temperature varies depending upon the surfactant and polymeric protective colloid used as well as the type of solvent. For example, in the case of hexaglyceryl monobehenylate and n-heptane, the temperature is 38 to 40~C. In the case of hexaglyceryl monobehenylate and cyclohexane, the temperature is 27 to 30~C and, in the case of sorbitan monostearate and n-heptane, the temperature is 29 to 31~C.
The amount of the aqueous solution of the water-soluble ethylenic monomer containing the radical polymerization initiator and optionally the crosslinking '- 2034293 agent used in the second and subsequent stages, which is absorbed to the water-containing gel obtained by the first stage polymerization, is 50 ~o 300~ by weight based on the total weight of the a~ueous water-soluble ethylenic unsaturated monomer solution of the first stage.
When the amount of the aqueous solution of the water-soluble ethylenic unsaturated monomer of the second and subsequent stages is less than 50% by weight, the various desired advantages of the present invention can hardly be expected. On the other hand, when the amount is more than 300% by weight, the monomer solution is not completely absorbed during absorption of the second and subsequent stages. This is undesirable because it forms a mass or extremely large coarse particles.
The following Examples further illustrate the present invention in detail but are not to be construed to limit the scope thereof.
In each Example, physical properties of the water-absorbent resin were determined according to the following methods.
(l) Absorbency A water-absorbent resin (l g) was dispersed in a 0.9% (w/w) aqueous solution of sodium chloride t200 ml), thoroughly swollen and then filtered through a 200 mesh metal wire net. The resulting swollen resin was weighed and the weight was taken as the absorbency.
~.
(2) Water-absorption rate (wettability) A water-absorbent resin (S g) was spread to a range of about 3.5 cm~ in a Petri dish. Then, a 0.9% (w/w) aqueous solution of sodium chloride (2 cc) was added dropwise to this by a pipette and the period of time required for complete absorption of water was measured and the time was taken as the water wettability.
(3) Integrity with a pulp (evaluation of integrity with a carrier pulp when the resin is to be used as an absorbent) A filter paper of ll cm~ was placed on a Petri dish and water (2 cc) was absorbed by the filter paper. A water-absorbent resin (2 g) was uniformly scattered on the filter paper. Then, the Petri dish was dried at 60~C for one hour and the amount of water-absorbent resin adhering to the filter paper was measured~ The amount was taken as the integrity.
(4) Measurement of reversion and diffusion A water-absorbent resin (5 g) was uniformly scattered on a pulp sheet having a weight of lO0 g/m2 which was cut to a size of 40 cm x 14 cm. The same pulp sheet as described above was laminated thereon and pressed by uniformly applying a pressure at 2 kg/cm2 on the entire pulp surface to obtain an absorbent.
1.6% (w/w) Aqueous solution of sodium chloride (150 ml) was poured on the center part of the absorbent thus prepared over l minute and the absorbent was allowed to 20~4293 stand for 10 minutes. Then, 20 sheets of filter paper ~No.
2, manufactured by Toyo Roshi Co., Ltd.) cut to a size of 10 cm x 10 cm were placed on the center part and pressed by placing a weight of 3.5 kg (bottom surface area: 10 cm x 10 cm) thereon. The amount of liquid reverted was determined by measuring the amount of liquid absorbed in the filter paper.
Further, diffusion length was determined by measuring spreading of the aqueous solution of sodium chloride.
Example 1 N-heptane (550 ml) was placed in a 1 liter four necked cylindrical round bottom flask equipped with a stirrer, a reflux condenser, a dropping funnel and a nitrogen gas inlet. To the flask was added hexaglyceryl monobehenylate having HLB of 13.1 (manufactured and sold by Nippon Oil and Fats Co., Ltd. under the trade mark Nonion GV-106) (1.38 g). The surfactant was dissolved by heating at 50~C and the mixture was cooled to 30~C. Separately, an 80% (w/w) aqueous solution of acrylic acid (92 g) was placed in a 500 ml conical flask and 20.1% (w/w) aqueous solution of sodium hydroxide (152.6 g) was added dropwise with external ice-cooling to neutralize 75 mol% of the acrylic acid. Potassium persulfate (0.11 g) was added to the mixture.
The resulting partially neutralized acrylic acid solution was added to the above four necked round bottom flask and the reaction system was thoroughly purged with t~
nitrogen gas. The reaction system was heated to carry out the first stage polymerization reaction, while maintaining the bath temperature at 70~C. The resulting polymerization slurry solution was cooled to 20~C, and the same amount of the partially neutralized acrylic acid solution prepared according to the same manner as described above was added dropwise to the reaction system and was allowed to absorb for 30 minutes. At the same time, the system was thoroughly purged with nitrogen gas. The system was heated and subjected to the second stage polymerization, while maintaining the bath temperature at 70~C. Water and n-heptane were distilled off and the residue was dried to obtain a water-absorbent resin (192.0 g) containing no fine powder and having a sharp particle size distribution.
Example 2 According to the same manner as described in Example 1, the polymerization was carried out except that ethylene glycol diglycidyl ether (each 18.4 mg) was added as a crosslinking agent to the partially neutralized aqueous acrylic acid solution used in polymerization of the first and second stages to obtain a water-absorbent resin (192.5 g) containing no fine powder and having a sharp particle size distribution.
Example 3 According to the same manner as described in Example 1, the polymerization was carried out except that the '~ 2034293 temperature in the system was adjusted to 25~C upon absorption of the partially neutralized aqueous acrylic acid solution used in the second stage polymerization to the polymerization solution of the first stage to obtain a water-absorbent resin (192.8 g) containing no fine powder and having a sharp particle size distribution.
Example 4 According to the same manner as described in Example 2, the polymerization was carried out except that 37% (w/w) aqueous solution of acrylamide (196.2 g) was used in place of the partially neutralized aqueous acrylic acid solution used in the second stage polymerization to obtain a water-absorbent resin (173.1 g) containing no fine powder and having a sharp particle size distribution.
Example 5 According to the same manner as described in Example 2, the polymerization was carried out except that an aqueous monomer solution prepared by mixing a partially neutralized aqueous acrylic acid solution, which was obtained by mixing 80% (w/w) aqueous solution of acrylic acid (46 g) and 14.6% (w/w) aqueous solution of sodium hydroxide (104.8 g) to neutralize 75 mol% of the acrylic acid, and 30% (w/w) aqueous solution of acrylamide (120.9 g) was used for the first and second stage polymerizations, respectively, in place of the partial~y neutralized aqueous acrylic acid solution used in Example 2 ~~ 18 to obtain a water-absorbent resin (172.5 g) containing no fine powder and having a sharp particle size distribution.
Example 6 According to the same manner as described in Example 1, the polymerization was carried out except that sorbitan monostearate having HLB of 4.7 (manufactured and sold by Nippon Oil and Fats Co., Ltd. under the trade mark of Nonion SP-60R) (2.76 g) was used in place of hexaglyceryl monobehenylate having HLB of 13.1 (Nonion GV-106) (1.38 g) and the temperature in the system was adjusted to 15~C upon the absorption of the partially neutralized acrylic acid solution used in the second stage polymerization to the first stage polymerization solution to obtain a water-absorbent resin (194.0 g) containing no fine powder and having a sharp ~5 particle size distribution.
Example 7 According to the same manner as described in Example 1, the polymerization was carried out except that sorbitan monolaurate having HLB of 8.6 (manufactured and sold by Nippon Oil and Fats Co., Ltd., Japan under the trade mark of Nonion LP-20R) (0.97 g) was used in place of hexaglyceryl monobehenylate having HLB of 13.1 (Nonion GV-106) (1.38 g), a partially neutralized aqueous acrylic acid solution used for the second stage polymerization was prepared by mixing 80%
(w/w) aqueous solution of acrylic acid (46 g) and 20.1% (w/w) aqueous solution of sodium hydroxide (76.3 g) to neutralize 75 mol% of the acrylic acid, and the temperature of the system was adjusted to 10~C upon the absorption of the monomer solution to the first stage polymerization solution to obtain a water-absorbent resin (143.9 g) containing no fine powder and having a sharp particle size distribution.
ExamPle 8 According to the same manner as described in Example 2, the polymerization was carried out except that a modified polyethylene wherein anhydrous maleic acid was added (manufactured and sold by Mitsui Petrochemical Industries Co., Ltd. under the trade mark of Hi-wax 1105A) (2.76 g) was used in place of hexaglyceryl monobehenylate having HLB of 13.1 (Nonion GV-106) (1.38 g) to obtain a water-absorbent resin (193.4 g) containing no fine powder and having a sharp particle size distribution.
Example 9 According to the same manner as described in Example 1, the polymerization was carried out except that sucrose di-tristearate having HLB of 3.0 (manufactured and 20 ~ ~
sold by Mitsubishi Chemical Food Industries Co., Ltd. under the trade mark of Sugar Ester S-370) (1.38 g) was used in place of hexaglyceryl monobehenylate having HLB of 13.1 (Nonion GV-106) (1.38 g) to obtain a water-absorbent resin (190.7 g) having no fine powder and a sharp particle size distribution.
ExamPle 10 According to the same manner as described in Example 1, the polymerization was carried out except that ethyl cellulose (manufactured and sold by Hercules Co., Ltd.
under the trade mark of Ethyl Cellulose N-22) (2.76 g) was used in place of hexaglyceryl monobehenylate having HLB of 13.1 (Nonion GV-106) (1.38 g), cyclohexane was used in place of n-heptane as the solvent, and the temperature of the system was adjusted to 10~C upon the absorption of a partially neutralized acrylic acid solution used in the second stage polymerization to the first stage polymerization solution to obtain a water-absorbent resin (193.2 g) having no fine powder and a sharp particle size distribution.
ExamPle 11 According to the same manner as described in Example 9, the polymerization was carried out except that a partially neutralized acrylic acid solution was used for the second stage pol-ymerization was prepared by mixing an 80~ (w~w) aqueous solution of acrylic acid (184 g) and 2 20.1% (w/w) aqueous solution of sodium hydroxide (305.2 g) to neutralize 75 mol% of the acrylic acid and then potassium persulfate was added thereto to obtain a water-absorbent resin (287.0 g) having no fine powder and a sharp particle size distribution.
Example 12 According to the same manner as described in Example 9, the polymerization was carried out except that polyethylene (n=14) glycol diacrylate (each 27.6 mg) was added as a crosslinking agent to both partially neutralized acrylic acid solutions used for both first and second stage polymerizations to obtain a water-absorbent resin (191.3 g) having no fine powder and a sharp particle size distribution.
Example 13 According to the same manner as described in Example 9, the polymerization was carried out except that N,N'-methylene bisacrylamide (each 18.4 mg) was added as a crosslinking agent to both partially neutralized acrylic acid solutions used for the first: and second stage polymerizations to obtain a water-absorbent resin (192.6 g) having no fine powder and a sharp particle size distribu-tion.
~ Example 14 20~293 According to the same manner as described in Example 2, the polymerization was carried out except that 28% (w/w) aqueous solution of methacrylamide (310.7 g) was used in place of the partially neutralized acrylic acidsolution used for the second stage polymerization to obtain a water-absorbent resin (188.5 g) having no fine powder and a sharp particle size distribution.
Example 15 According to the same manner as described in Example 13, the polymerization was carried out except that 25% (w/w) aqueous solution of N,N-dimethylacrylamide (404.8 g) was used in place of the partially neutralized acrylic acid solution used for the second stage polymerization to obtain a water-absorbent resin (203.3 g) having no fine powder and a sharp particle size distributi~n.
Example 16 According to the same manner as described in Example 2, the polymerization was carried out except that 30% (w/w) aqueous solution of acrylamide (242 g) was used in place of the partially neutralized acrylic acid solution used for the first stage polymeri7ation and ~,N'-methylene bisacrylamide (each 18.4 mg) was used in place of ethylene glycol diglycidyl ether used for both first and second stage polymerizations to obtain a water-absorbent resin (172.9 g) having no fine powder and a sharp particle size distribution.
ExamPle 17 According to the same manner as described in Example 2, the polymerization was carried out except that hexaglyceryl monobehenylate having HLB of 13.1 (0.92 g) was used in combination with a modified polyethylene wherein anhydrous maleic acid (Hi-wax 1105A) was added (0.92 g) and the temperature of the system was adjusted to 30~C upon absorption of the partially neutralized acrylic acid solution used for the second stage polymerization to the first stage polymerization solution to obtain a water-absorbent resin (192.4 g) having no fine powder and a sharp particle size distribution.
Example 18 After completion of the second stage polymerization according to Example 1, the resulting polymerization slurry solution was cooled to 20~C. Separately, 80% (w/w) aqueous solution of acrylic acid (92 g) and 20.1% (w/w) aqueous solution of sodium hydroxide (152.6 g) were mixed to neutralize 75 mol% of the acrylic acid. Ethylene glycol diglycidyl ether (36.8 g) was added to the mixture and potassium persulfate (0.11 g) was further added. The resulting partially neutralized acrylic acid solution was added dropwise to the above reaction system and 2 ~ 3 4 2 ~ 3 absorbed for 30 minutes. At the same time, the reaction system was thoroughly purged with nitrogen gas. The system was heated and subjected to a third stage polymerization, while maintaining the bath temperature at 70~C.
Water and n-heptane were distilled off and the residue was dried to obtain a water-absorbent resin (287,5 g) having no fine powder and a sharp particle size distribution.
Comparative Example 1 N-heptane (550 ml) was placed in a 1 liter four necked cylindrical round bottom flask equipped with a stirrer, a reflux condenser, a dropping funnel and a nitrogen gas inlet. Hexaglyceryl monobehenylate having HLB of 13.1 (Nonion GV-106) (1.38 g) was added to the flask. After heating at 50~C to dissolve the surfactant, the mixture was cooled to 30~C. Separately, 80%
(w/w) aqueous solution of acrylic acid (92 g) was placed in a 500 ml conical flask and 20.1% (w/w) aqueous solution of sodium hydroxide (152.6 9) was added dropwise with external ice-cooling to neutralize 75 mol% of the acrylic acid.
Potassium persulfate (0.11 9) was added to the mixture and dissolved. The resulting partially neutralized acrylic acid solution was added to the above four necked round bottom flask and the reaction system was thoroughly purged with nitrogen gas. The reaction system was heated and subjected 25 ~ ~ ~4~3 to the polymerization reaction, while maintaining the bath temperature at 70~C. Water and n-heptane were distilled off and the residue was dried to obtain a water-absorbent resin (96.7 g).
Comparative Example 2 According to the same manner as described in Comparative Example 1, the polymerization was carried out except that sorbitan monostearate having HLB of 4.7 (Nonion SP-60R) (2.76 g) was used in place of hexaglyceryl monobehenylate having HLB of 13.1 (Nonion GV-106) (1.38 g) to obtain a water-absorbent resin (98.2 g).
Comparative Example 3 According to the same manner as described in Comparative Example 1, the polymerization was carried out except that sorbitan monolaurate having HLB of 8.6 (Nonion LP-20R) (0.97 g) was used in place of hexaglyceryl monobeheny-late having HLB of 13.1 (Nonion GV-106) (1.38 g) to obtain a water-absorbent resin (96.0 g).
Comparative Example 4 According to the same manner as described in Comparative Example 1, the polymerization was carried out except that modified polyethylene wherein anhydrous maleic TM
acid was added (Hi-wax 1105A) (2.76 g) was used in place of hexaglyceryl monobehenylate having HLB of 13.1 (Nonion GV-106) (1.38 g) to obtain a water-absorbent resin (~8.0 g).
B
203~293 '~ 26 ComParative Example 5 According to the same manner as described in Comparative Example 1, the polymerization was carried out except that sucrose di-tristearate having HLB of 3.0 (Sugar Ester S-370) (1.38 g) was used in place of hexaglyceryl monobehenylate having HLB of 13.1 (Nonion GV-106) (1.38 g) to obtain a water-absorbent resin (97.1 g).
ComParative Example 6 According to the same manner as described in Comparative Example 1, the polymerization was carried out except that ethyl cellulose (Ethyl Cellulose N-22) (2.76 g) was used in place of hexaglyceryl monobehenylate having HLB of 13.1 (Nonion GV-106) (1.38 g) and cyclohexane was used in place of n-heptane to obtain a water-absorbent resin (98.2 g).
Comparative ExamPle 7 According to the same manner as described in Example 1, the polymerization was carried out except that the temperature of the system was adjusted to 45~C upon absorption of a partially neutralized acrylic acid solution used for the second stage polymerization to the first stage polymerization solution to obtain a water-absorbent resin (192.5 g).
Properties of the water-absorbent resins obtained in the above Examples and Comparative Examples are shown in Table 1 below.
2Q~293 E ~ ~-- ~ o -- ~ -- _ o ~ ~
. . . . . . . . . . . . . . .
~-- o o o _ o ~ U~ o o ~ o _ o C~ ~ o C O
~ C~
,_ u .1 o o o o o o o o o o o o o o o o ~ r~
¢ U~
C
.,~
u~ E o c~ o C
.,, 'J '_ o o o ~ _ ~ ~ o o o o o o -- o o c ., b~ ~ ~u~ ~ c~ ~ O O ~ O .;r c~
JJ
_, ., ~ ?~
~ ~J
3 '---D' _ oIn ~ o 0C~uc a~ O C~
E~ L~. _, <
. .
X X X X X X X L~ X X X X X X X ~
Table 1 (continued) Absorbency Water-absorption rate Integrity Reversion Diffusion Average particle Fine powder (g/g)(wettability) (sec.) (%) (g) (cm)size ( ~m)F100 ~m Ex. 17 56 4 83 0.3 30 370 1.3 Ex. 18 67 3 90 0.4 30 470 0.2 Comp.
Ex. 1 72 25 43 4.5 25 200 12 Comp.
Ex. 2 70 30 35 7.4 22 95 69.3 Comp.
Ex. 3 75 8 68 15.9 18 250 15 Comp.
Ex. 4 81 35 47 5.5 23 260 14 Comp.
Ex. 5 73 29 38 5.0 21 190 26 Comp.
Ex. 6 74 12 69 4.7 24 270 7 Comp.
Ex. 7 70 7 71 5.1 23 195 17 o CS~
C~
29 203429~
_ The water-absorbent resin obtained by the process of the present invention is suitable for use in the sanitary field, the soil conditioning field and the industrial field and the like, particularly, for the sanitary field. That is, since the water-absorbent resin obtained by the process of the present invention has large particle size, less fine powder and a sharp particle size distribution, it has the following advantages. Firstly, in diapers and the like, reversion is inhibited and diffusion of absorbed substances is good.
Secondly, the water-absorbent resin fixes well to a pulp and a good absorbent article can be obtained. Thirdly, in the case of spreading the water-absorbent resin with a spreader, non-uniform spreading is prevented and it is easy to maintain a constant spread. Further, since the amount of the surfactant or polymeric protective colloid in the surface layer of the water-absorbent resin is small, initial water-absorption rate, i.e., wettability is improved. Furthermore, in the case of fixing the water-absorbent resin to a pulp, integrity of the water-absorbent resin with the pulp is improved and an absorbent article wherein the resin does not separate is obtained. In addition, since productivity is improved, a cheap water-absorbent resin can be provided. As described hereinabove, the water-absorbent resin obtained by the process of the present invention has excellent properties and is particularly useful in the sanitary field because of these various advantages.
1.6% (w/w) Aqueous solution of sodium chloride (150 ml) was poured on the center part of the absorbent thus prepared over l minute and the absorbent was allowed to 20~4293 stand for 10 minutes. Then, 20 sheets of filter paper ~No.
2, manufactured by Toyo Roshi Co., Ltd.) cut to a size of 10 cm x 10 cm were placed on the center part and pressed by placing a weight of 3.5 kg (bottom surface area: 10 cm x 10 cm) thereon. The amount of liquid reverted was determined by measuring the amount of liquid absorbed in the filter paper.
Further, diffusion length was determined by measuring spreading of the aqueous solution of sodium chloride.
Example 1 N-heptane (550 ml) was placed in a 1 liter four necked cylindrical round bottom flask equipped with a stirrer, a reflux condenser, a dropping funnel and a nitrogen gas inlet. To the flask was added hexaglyceryl monobehenylate having HLB of 13.1 (manufactured and sold by Nippon Oil and Fats Co., Ltd. under the trade mark Nonion GV-106) (1.38 g). The surfactant was dissolved by heating at 50~C and the mixture was cooled to 30~C. Separately, an 80% (w/w) aqueous solution of acrylic acid (92 g) was placed in a 500 ml conical flask and 20.1% (w/w) aqueous solution of sodium hydroxide (152.6 g) was added dropwise with external ice-cooling to neutralize 75 mol% of the acrylic acid. Potassium persulfate (0.11 g) was added to the mixture.
The resulting partially neutralized acrylic acid solution was added to the above four necked round bottom flask and the reaction system was thoroughly purged with t~
nitrogen gas. The reaction system was heated to carry out the first stage polymerization reaction, while maintaining the bath temperature at 70~C. The resulting polymerization slurry solution was cooled to 20~C, and the same amount of the partially neutralized acrylic acid solution prepared according to the same manner as described above was added dropwise to the reaction system and was allowed to absorb for 30 minutes. At the same time, the system was thoroughly purged with nitrogen gas. The system was heated and subjected to the second stage polymerization, while maintaining the bath temperature at 70~C. Water and n-heptane were distilled off and the residue was dried to obtain a water-absorbent resin (192.0 g) containing no fine powder and having a sharp particle size distribution.
Example 2 According to the same manner as described in Example 1, the polymerization was carried out except that ethylene glycol diglycidyl ether (each 18.4 mg) was added as a crosslinking agent to the partially neutralized aqueous acrylic acid solution used in polymerization of the first and second stages to obtain a water-absorbent resin (192.5 g) containing no fine powder and having a sharp particle size distribution.
Example 3 According to the same manner as described in Example 1, the polymerization was carried out except that the '~ 2034293 temperature in the system was adjusted to 25~C upon absorption of the partially neutralized aqueous acrylic acid solution used in the second stage polymerization to the polymerization solution of the first stage to obtain a water-absorbent resin (192.8 g) containing no fine powder and having a sharp particle size distribution.
Example 4 According to the same manner as described in Example 2, the polymerization was carried out except that 37% (w/w) aqueous solution of acrylamide (196.2 g) was used in place of the partially neutralized aqueous acrylic acid solution used in the second stage polymerization to obtain a water-absorbent resin (173.1 g) containing no fine powder and having a sharp particle size distribution.
Example 5 According to the same manner as described in Example 2, the polymerization was carried out except that an aqueous monomer solution prepared by mixing a partially neutralized aqueous acrylic acid solution, which was obtained by mixing 80% (w/w) aqueous solution of acrylic acid (46 g) and 14.6% (w/w) aqueous solution of sodium hydroxide (104.8 g) to neutralize 75 mol% of the acrylic acid, and 30% (w/w) aqueous solution of acrylamide (120.9 g) was used for the first and second stage polymerizations, respectively, in place of the partial~y neutralized aqueous acrylic acid solution used in Example 2 ~~ 18 to obtain a water-absorbent resin (172.5 g) containing no fine powder and having a sharp particle size distribution.
Example 6 According to the same manner as described in Example 1, the polymerization was carried out except that sorbitan monostearate having HLB of 4.7 (manufactured and sold by Nippon Oil and Fats Co., Ltd. under the trade mark of Nonion SP-60R) (2.76 g) was used in place of hexaglyceryl monobehenylate having HLB of 13.1 (Nonion GV-106) (1.38 g) and the temperature in the system was adjusted to 15~C upon the absorption of the partially neutralized acrylic acid solution used in the second stage polymerization to the first stage polymerization solution to obtain a water-absorbent resin (194.0 g) containing no fine powder and having a sharp ~5 particle size distribution.
Example 7 According to the same manner as described in Example 1, the polymerization was carried out except that sorbitan monolaurate having HLB of 8.6 (manufactured and sold by Nippon Oil and Fats Co., Ltd., Japan under the trade mark of Nonion LP-20R) (0.97 g) was used in place of hexaglyceryl monobehenylate having HLB of 13.1 (Nonion GV-106) (1.38 g), a partially neutralized aqueous acrylic acid solution used for the second stage polymerization was prepared by mixing 80%
(w/w) aqueous solution of acrylic acid (46 g) and 20.1% (w/w) aqueous solution of sodium hydroxide (76.3 g) to neutralize 75 mol% of the acrylic acid, and the temperature of the system was adjusted to 10~C upon the absorption of the monomer solution to the first stage polymerization solution to obtain a water-absorbent resin (143.9 g) containing no fine powder and having a sharp particle size distribution.
ExamPle 8 According to the same manner as described in Example 2, the polymerization was carried out except that a modified polyethylene wherein anhydrous maleic acid was added (manufactured and sold by Mitsui Petrochemical Industries Co., Ltd. under the trade mark of Hi-wax 1105A) (2.76 g) was used in place of hexaglyceryl monobehenylate having HLB of 13.1 (Nonion GV-106) (1.38 g) to obtain a water-absorbent resin (193.4 g) containing no fine powder and having a sharp particle size distribution.
Example 9 According to the same manner as described in Example 1, the polymerization was carried out except that sucrose di-tristearate having HLB of 3.0 (manufactured and 20 ~ ~
sold by Mitsubishi Chemical Food Industries Co., Ltd. under the trade mark of Sugar Ester S-370) (1.38 g) was used in place of hexaglyceryl monobehenylate having HLB of 13.1 (Nonion GV-106) (1.38 g) to obtain a water-absorbent resin (190.7 g) having no fine powder and a sharp particle size distribution.
ExamPle 10 According to the same manner as described in Example 1, the polymerization was carried out except that ethyl cellulose (manufactured and sold by Hercules Co., Ltd.
under the trade mark of Ethyl Cellulose N-22) (2.76 g) was used in place of hexaglyceryl monobehenylate having HLB of 13.1 (Nonion GV-106) (1.38 g), cyclohexane was used in place of n-heptane as the solvent, and the temperature of the system was adjusted to 10~C upon the absorption of a partially neutralized acrylic acid solution used in the second stage polymerization to the first stage polymerization solution to obtain a water-absorbent resin (193.2 g) having no fine powder and a sharp particle size distribution.
ExamPle 11 According to the same manner as described in Example 9, the polymerization was carried out except that a partially neutralized acrylic acid solution was used for the second stage pol-ymerization was prepared by mixing an 80~ (w~w) aqueous solution of acrylic acid (184 g) and 2 20.1% (w/w) aqueous solution of sodium hydroxide (305.2 g) to neutralize 75 mol% of the acrylic acid and then potassium persulfate was added thereto to obtain a water-absorbent resin (287.0 g) having no fine powder and a sharp particle size distribution.
Example 12 According to the same manner as described in Example 9, the polymerization was carried out except that polyethylene (n=14) glycol diacrylate (each 27.6 mg) was added as a crosslinking agent to both partially neutralized acrylic acid solutions used for both first and second stage polymerizations to obtain a water-absorbent resin (191.3 g) having no fine powder and a sharp particle size distribution.
Example 13 According to the same manner as described in Example 9, the polymerization was carried out except that N,N'-methylene bisacrylamide (each 18.4 mg) was added as a crosslinking agent to both partially neutralized acrylic acid solutions used for the first: and second stage polymerizations to obtain a water-absorbent resin (192.6 g) having no fine powder and a sharp particle size distribu-tion.
~ Example 14 20~293 According to the same manner as described in Example 2, the polymerization was carried out except that 28% (w/w) aqueous solution of methacrylamide (310.7 g) was used in place of the partially neutralized acrylic acidsolution used for the second stage polymerization to obtain a water-absorbent resin (188.5 g) having no fine powder and a sharp particle size distribution.
Example 15 According to the same manner as described in Example 13, the polymerization was carried out except that 25% (w/w) aqueous solution of N,N-dimethylacrylamide (404.8 g) was used in place of the partially neutralized acrylic acid solution used for the second stage polymerization to obtain a water-absorbent resin (203.3 g) having no fine powder and a sharp particle size distributi~n.
Example 16 According to the same manner as described in Example 2, the polymerization was carried out except that 30% (w/w) aqueous solution of acrylamide (242 g) was used in place of the partially neutralized acrylic acid solution used for the first stage polymeri7ation and ~,N'-methylene bisacrylamide (each 18.4 mg) was used in place of ethylene glycol diglycidyl ether used for both first and second stage polymerizations to obtain a water-absorbent resin (172.9 g) having no fine powder and a sharp particle size distribution.
ExamPle 17 According to the same manner as described in Example 2, the polymerization was carried out except that hexaglyceryl monobehenylate having HLB of 13.1 (0.92 g) was used in combination with a modified polyethylene wherein anhydrous maleic acid (Hi-wax 1105A) was added (0.92 g) and the temperature of the system was adjusted to 30~C upon absorption of the partially neutralized acrylic acid solution used for the second stage polymerization to the first stage polymerization solution to obtain a water-absorbent resin (192.4 g) having no fine powder and a sharp particle size distribution.
Example 18 After completion of the second stage polymerization according to Example 1, the resulting polymerization slurry solution was cooled to 20~C. Separately, 80% (w/w) aqueous solution of acrylic acid (92 g) and 20.1% (w/w) aqueous solution of sodium hydroxide (152.6 g) were mixed to neutralize 75 mol% of the acrylic acid. Ethylene glycol diglycidyl ether (36.8 g) was added to the mixture and potassium persulfate (0.11 g) was further added. The resulting partially neutralized acrylic acid solution was added dropwise to the above reaction system and 2 ~ 3 4 2 ~ 3 absorbed for 30 minutes. At the same time, the reaction system was thoroughly purged with nitrogen gas. The system was heated and subjected to a third stage polymerization, while maintaining the bath temperature at 70~C.
Water and n-heptane were distilled off and the residue was dried to obtain a water-absorbent resin (287,5 g) having no fine powder and a sharp particle size distribution.
Comparative Example 1 N-heptane (550 ml) was placed in a 1 liter four necked cylindrical round bottom flask equipped with a stirrer, a reflux condenser, a dropping funnel and a nitrogen gas inlet. Hexaglyceryl monobehenylate having HLB of 13.1 (Nonion GV-106) (1.38 g) was added to the flask. After heating at 50~C to dissolve the surfactant, the mixture was cooled to 30~C. Separately, 80%
(w/w) aqueous solution of acrylic acid (92 g) was placed in a 500 ml conical flask and 20.1% (w/w) aqueous solution of sodium hydroxide (152.6 9) was added dropwise with external ice-cooling to neutralize 75 mol% of the acrylic acid.
Potassium persulfate (0.11 9) was added to the mixture and dissolved. The resulting partially neutralized acrylic acid solution was added to the above four necked round bottom flask and the reaction system was thoroughly purged with nitrogen gas. The reaction system was heated and subjected 25 ~ ~ ~4~3 to the polymerization reaction, while maintaining the bath temperature at 70~C. Water and n-heptane were distilled off and the residue was dried to obtain a water-absorbent resin (96.7 g).
Comparative Example 2 According to the same manner as described in Comparative Example 1, the polymerization was carried out except that sorbitan monostearate having HLB of 4.7 (Nonion SP-60R) (2.76 g) was used in place of hexaglyceryl monobehenylate having HLB of 13.1 (Nonion GV-106) (1.38 g) to obtain a water-absorbent resin (98.2 g).
Comparative Example 3 According to the same manner as described in Comparative Example 1, the polymerization was carried out except that sorbitan monolaurate having HLB of 8.6 (Nonion LP-20R) (0.97 g) was used in place of hexaglyceryl monobeheny-late having HLB of 13.1 (Nonion GV-106) (1.38 g) to obtain a water-absorbent resin (96.0 g).
Comparative Example 4 According to the same manner as described in Comparative Example 1, the polymerization was carried out except that modified polyethylene wherein anhydrous maleic TM
acid was added (Hi-wax 1105A) (2.76 g) was used in place of hexaglyceryl monobehenylate having HLB of 13.1 (Nonion GV-106) (1.38 g) to obtain a water-absorbent resin (~8.0 g).
B
203~293 '~ 26 ComParative Example 5 According to the same manner as described in Comparative Example 1, the polymerization was carried out except that sucrose di-tristearate having HLB of 3.0 (Sugar Ester S-370) (1.38 g) was used in place of hexaglyceryl monobehenylate having HLB of 13.1 (Nonion GV-106) (1.38 g) to obtain a water-absorbent resin (97.1 g).
ComParative Example 6 According to the same manner as described in Comparative Example 1, the polymerization was carried out except that ethyl cellulose (Ethyl Cellulose N-22) (2.76 g) was used in place of hexaglyceryl monobehenylate having HLB of 13.1 (Nonion GV-106) (1.38 g) and cyclohexane was used in place of n-heptane to obtain a water-absorbent resin (98.2 g).
Comparative ExamPle 7 According to the same manner as described in Example 1, the polymerization was carried out except that the temperature of the system was adjusted to 45~C upon absorption of a partially neutralized acrylic acid solution used for the second stage polymerization to the first stage polymerization solution to obtain a water-absorbent resin (192.5 g).
Properties of the water-absorbent resins obtained in the above Examples and Comparative Examples are shown in Table 1 below.
2Q~293 E ~ ~-- ~ o -- ~ -- _ o ~ ~
. . . . . . . . . . . . . . .
~-- o o o _ o ~ U~ o o ~ o _ o C~ ~ o C O
~ C~
,_ u .1 o o o o o o o o o o o o o o o o ~ r~
¢ U~
C
.,~
u~ E o c~ o C
.,, 'J '_ o o o ~ _ ~ ~ o o o o o o -- o o c ., b~ ~ ~u~ ~ c~ ~ O O ~ O .;r c~
JJ
_, ., ~ ?~
~ ~J
3 '---D' _ oIn ~ o 0C~uc a~ O C~
E~ L~. _, <
. .
X X X X X X X L~ X X X X X X X ~
Table 1 (continued) Absorbency Water-absorption rate Integrity Reversion Diffusion Average particle Fine powder (g/g)(wettability) (sec.) (%) (g) (cm)size ( ~m)F100 ~m Ex. 17 56 4 83 0.3 30 370 1.3 Ex. 18 67 3 90 0.4 30 470 0.2 Comp.
Ex. 1 72 25 43 4.5 25 200 12 Comp.
Ex. 2 70 30 35 7.4 22 95 69.3 Comp.
Ex. 3 75 8 68 15.9 18 250 15 Comp.
Ex. 4 81 35 47 5.5 23 260 14 Comp.
Ex. 5 73 29 38 5.0 21 190 26 Comp.
Ex. 6 74 12 69 4.7 24 270 7 Comp.
Ex. 7 70 7 71 5.1 23 195 17 o CS~
C~
29 203429~
_ The water-absorbent resin obtained by the process of the present invention is suitable for use in the sanitary field, the soil conditioning field and the industrial field and the like, particularly, for the sanitary field. That is, since the water-absorbent resin obtained by the process of the present invention has large particle size, less fine powder and a sharp particle size distribution, it has the following advantages. Firstly, in diapers and the like, reversion is inhibited and diffusion of absorbed substances is good.
Secondly, the water-absorbent resin fixes well to a pulp and a good absorbent article can be obtained. Thirdly, in the case of spreading the water-absorbent resin with a spreader, non-uniform spreading is prevented and it is easy to maintain a constant spread. Further, since the amount of the surfactant or polymeric protective colloid in the surface layer of the water-absorbent resin is small, initial water-absorption rate, i.e., wettability is improved. Furthermore, in the case of fixing the water-absorbent resin to a pulp, integrity of the water-absorbent resin with the pulp is improved and an absorbent article wherein the resin does not separate is obtained. In addition, since productivity is improved, a cheap water-absorbent resin can be provided. As described hereinabove, the water-absorbent resin obtained by the process of the present invention has excellent properties and is particularly useful in the sanitary field because of these various advantages.
Claims (16)
1. A process for the production of a water-absorbent resin by reversed phase suspension polymerization of a water-soluble ethylenic unsaturated monomer which comprises subjecting an aqueous solution of the water-soluble ethylenic unsaturated monomer to a reversed phase suspension polymerization reaction in a first stage in a petroleum hydrocarbon solvent in the presence of a surfactant and/or polymeric protective colloid in an amount of 0.1 to 5% by weight using a radical polymerization initiator optionally in the presence of a crosslinking agent, cooling the solution to precipitate the surfactant and/or polymeric protective colloid, as a first polymerization reaction system and then repeating the polymerization by adding an aqueous solution of a water-soluble ethylenic unsaturated monomer solution containing a radical polymerization initiator and optionally a crosslinking agent to the first polymerization reaction system to carry out a further reversed phase suspension polymerization reaction, at least, once as a second and subsequent polymerization stages.
2. A process according to claim 1, wherein the reversed phase suspension polymerization reaction is carried out in two stages and, upon the second stage polymerization, the aqueous solution of the water-soluble ethylenic unsaturated monomer solution containing the radical polymerization initiator and optionally the crosslinking agent is added to the first stage polymerization system in a ratio of 50 to 300% by weight based on the weight of the monomer solution of the first stage.
3. A process according to claim 1, wherein the monomer component used in the second and subsequent stages is a member selected from water-soluble ethylenic unsaturated monomers which are the same as or different from the monomer component used in the first stage.
4. A process according to claim 1, wherein the water-soluble ethylenic unsaturated monomer used in the first and subsequent stage is acrylic acid, methacrylic acid or an alkali salt thereof.
5. A process according to claim 1, wherein the water-soluble ethylenic unsaturated monomer used in the first and subsequent stage is acrylamide, methacrylamide or N,N-dimethylacrylamide.
6. A process according to claim 1, wherein the surfactant is a nonionic surfactant, or a combination of a nonionic surfactant and an anionic surfactant.
7. A process according to claim 6, wherein the surfactant is one or more members selected from the group consisting of sorbitan fatty acid esters, polyglycerin fatty acid esters, sucrose fatty acid esters and sorbitol fatty acid esters.
8. A process according to claim 1, wherein the polymeric protective colloid is one or more members selected from the group consisting of ethyl cellulose, ethyl hydroxyethyl cellulose, oxidized polyethylene, polyethylene modified with maleic anhydride, polybutadiene modified with maleic anhydride and ethylene-propylene-diene-terpolymer modified with maleic anhydride.
9. A process according to claim 1, wherein the petroleum hydrocarbon solvent is one or more members selected from the group consisting of n-hexane, n-heptane, cyclohexane, toluene and xylene.
10. A process according to claim 1, wherein the aqueous solution of water-soluble ethylenic unsaturated monomer used in each stage contains the monomer in a concentration of not less than 25% by weight.
11. A process according to claim 9, wherein the petroleum hydrocarbon solvent is n-heptane.
12. A process according to claim 1, wherein the radical polymerization initiator is potassium persulfate.
13. A process according to claim 1, wherein the crosslinking agent is ethylene glycol diglycidyl ether or polyethylene glycol diglycidyl ether.
14. A process according to claim 1, wherein the crosslinking agent is ethylene glycol diacrylate, ethylene glycol dimethacrylate, polyethylene glycol diacrylate or polyethylene glycol dimethacrylate.
15. A process according to claim 1, wherein the crosslinking agent is N,N'-methylene bisacrylamide.
16. A process according to claim 1, wherein the reversed phase suspension polymerization reaction is carried out in three or more stages.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22774/1990 | 1990-01-31 | ||
| JP2022774A JP2938920B2 (en) | 1990-01-31 | 1990-01-31 | Method for producing water absorbent resin |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2034293A1 CA2034293A1 (en) | 1991-08-01 |
| CA2034293C true CA2034293C (en) | 1999-05-04 |
Family
ID=12092015
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002034293A Expired - Lifetime CA2034293C (en) | 1990-01-31 | 1991-01-16 | Process for production of water-absorbent resin |
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| Country | Link |
|---|---|
| US (1) | US5180798A (en) |
| EP (1) | EP0441507B1 (en) |
| JP (1) | JP2938920B2 (en) |
| KR (1) | KR0174745B1 (en) |
| CN (1) | CN1023486C (en) |
| BR (1) | BR9100398A (en) |
| CA (1) | CA2034293C (en) |
| DE (1) | DE69118224T2 (en) |
| ES (1) | ES2087967T3 (en) |
| TW (1) | TW228528B (en) |
Families Citing this family (118)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3175791B2 (en) * | 1992-06-10 | 2001-06-11 | 株式会社日本触媒 | Manufacturing method of water absorbing agent |
| FR2694755B1 (en) * | 1992-08-12 | 1994-09-23 | Atochem Elf Sa | Improvement for the preparation of superabsorbent powder by reverse suspension polymerization of acrylic monomers. |
| FR2694757B1 (en) * | 1992-08-12 | 1994-10-07 | Atochem Elf Sa | Process for the preparation of superabsorbent polyacrylates with a low content of residual monomers. |
| FR2694756B1 (en) * | 1992-08-12 | 1994-10-07 | Atochem Elf Sa | Improvement for the preparation of superabsorbent polyacrylates. |
| JP3005124B2 (en) * | 1992-09-10 | 2000-01-31 | 花王株式会社 | Method for producing amorphous polymer particles |
| FR2710342B1 (en) * | 1993-09-21 | 1995-11-17 | Atochem Elf Sa | Superabsorbent acrylic polymers with improved properties and process for obtaining them. |
| GB9413605D0 (en) * | 1994-07-06 | 1994-08-24 | American Colloid Co | Method of increasing the size and absorption under load of super-absorbent fine particles by impregnation with an aqueous acrylic monomer solution |
| US5549590A (en) * | 1994-08-01 | 1996-08-27 | Leonard Pearlstein | High performance absorbent particles and methods of preparation |
| US5849816A (en) * | 1994-08-01 | 1998-12-15 | Leonard Pearlstein | Method of making high performance superabsorbent material |
| FR2732973B1 (en) * | 1995-04-11 | 1997-06-13 | Atochem Elf Sa | PROCESS FOR OBTAINING SUPERABSORBENT POLYMERS FOR WATER AND AQUEOUS FLUIDS IN THE FORM OF PARTICLE AGGREGATES |
| JPH0912613A (en) * | 1995-06-28 | 1997-01-14 | Mitsubishi Chem Corp | Method for producing water absorbent resin |
| JP4072833B2 (en) * | 1995-11-30 | 2008-04-09 | 住友精化株式会社 | Method for producing water absorbent resin and water absorbent resin |
| FR2744456A1 (en) | 1996-02-07 | 1997-08-08 | Atochem Elf Sa | SUPERABSORBENT POLYMERS WITH A HEART-SHELL STRUCTURE AND THEIR PROCESS FOR OBTAINING |
| FR2748404B1 (en) * | 1996-05-09 | 1998-07-24 | Atochem Elf Sa | SUPER ABSORBENT POWDERS WITH HIGH ABSORPTION AND HIGH HAIR SUCION |
| FR2755693B1 (en) * | 1996-11-14 | 1998-12-18 | Atochem Elf Sa | PROCESS FOR OBTAINING HYDROPHILIC POLYMERS WITH HIGH SPEED OF DISSOLUTION OR SWELLING IN WATER |
| JP3871445B2 (en) * | 1998-09-02 | 2007-01-24 | 花王株式会社 | Production method of super absorbent resin |
| DE50013652D1 (en) | 1999-06-09 | 2006-12-07 | Wella Ag | Use of solid, gasified particles for hair treatments and hair treatment compositions containing them |
| US6414080B1 (en) * | 1999-06-09 | 2002-07-02 | Calgon Corporation | Inverse emulsion polymer and production thereof |
| KR100573865B1 (en) * | 1999-08-31 | 2006-04-25 | 주식회사 새 한 | Manufacturing method of polyester fabric excellent in water repellency and antistatic property |
| JP4766812B2 (en) * | 1999-11-19 | 2011-09-07 | 株式会社日本触媒 | Method for producing porous crosslinked polymer material |
| US7083810B2 (en) | 2000-04-19 | 2006-08-01 | Wella Aktiengesellschaft | Cosmetic agent in the form of a gel |
| KR100431536B1 (en) * | 2001-02-14 | 2004-05-20 | 박상규 | Food quality indicator using pH sensitive indicator |
| BR0204831A (en) * | 2001-04-16 | 2003-04-29 | Sumitomo Seika Chemicals | Water absorbent resin suitable for absorbing polymer-containing viscous liquids, and absorbent core and absorbent article using the same |
| DE10150765A1 (en) | 2001-10-13 | 2003-04-17 | Wella Ag | Lace film for winding hair and process for permanent hair shaping |
| DE60233590D1 (en) * | 2001-12-19 | 2009-10-15 | Nippon Catalytic Chem Ind | ACRYLIC ACID COMPOSITION AND METHOD FOR THE PRODUCTION THEREOF, METHOD FOR PRODUCING WATER ABSORBENT RESIN, RESIN COMPOUNDS TO THE ACRYLIC ACIDIC ACID |
| JP3940009B2 (en) * | 2002-03-18 | 2007-07-04 | 住友精化株式会社 | Method for producing carboxyl group-containing water-soluble polymer |
| DE10308317A1 (en) * | 2003-02-26 | 2004-09-09 | Giesecke & Devrient Gmbh | Process for producing a resist substrate |
| EP1609810B1 (en) | 2003-03-17 | 2013-01-16 | Sumitomo Seika Chemicals Co., Ltd. | Process for production of water-absorbing resin particles |
| CN100379764C (en) * | 2003-05-13 | 2008-04-09 | 住友精化株式会社 | Method for producing water-absorbing resin |
| JP4736316B2 (en) * | 2003-10-21 | 2011-07-27 | Ｄｉｃ株式会社 | Manufacturing method of super absorbent resin |
| KR101184238B1 (en) * | 2003-12-25 | 2012-09-21 | 스미또모 세이까 가부시키가이샤 | Method for producing water-absorbing resin |
| JP4969778B2 (en) * | 2004-12-21 | 2012-07-04 | 住友精化株式会社 | Method for producing water-absorbent resin particles and sanitary material using the same |
| KR100626552B1 (en) * | 2005-04-06 | 2006-09-22 | 김수동 | Preparation of Polyacrylamide Copolymer Containing Less Residual Monomer and Initiator Residue |
| TWI353360B (en) * | 2005-04-07 | 2011-12-01 | Nippon Catalytic Chem Ind | Production process of polyacrylic acid (salt) wate |
| US8084544B2 (en) | 2005-07-04 | 2011-12-27 | Sumitomo Seika Chemicals Co., Ltd. | Process for production of water-absorbing resin |
| JP4646830B2 (en) * | 2005-10-27 | 2011-03-09 | 花王株式会社 | Absorbent articles |
| TWI394789B (en) | 2005-12-22 | 2013-05-01 | Nippon Catalytic Chem Ind | Water-absorbent resin composition, method of manufacturing the same, and absorbent article |
| CN100443554C (en) * | 2006-03-23 | 2008-12-17 | 中国地质大学（武汉） | Preparation method of superabsorbent and water-retaining composite material containing framework silicate mineral |
| CN100443553C (en) * | 2006-03-23 | 2008-12-17 | 中国地质大学（武汉） | Preparation method of superabsorbent and water-retaining composite material containing amorphous silicate mineral |
| EP1837348B9 (en) | 2006-03-24 | 2020-01-08 | Nippon Shokubai Co.,Ltd. | Water-absorbing resin and method for manufacturing the same |
| WO2007123188A1 (en) | 2006-04-24 | 2007-11-01 | Sumitomo Seika Chemicals Co., Ltd. | Process for production of water-absorbable resin particle, and water-absorbable resin particle produced by the process |
| JP5378790B2 (en) * | 2006-04-27 | 2013-12-25 | 住友精化株式会社 | Method for producing water absorbent resin |
| US7989367B2 (en) * | 2006-06-30 | 2011-08-02 | Georgia-Pacific Chemicals Llc | Reducing formaldehyde emissions from fiberglass insulation |
| WO2008127287A2 (en) | 2006-10-11 | 2008-10-23 | Biolife, L.L.C. | Materials and methods for wound treatment |
| CA2675026A1 (en) * | 2007-01-12 | 2008-07-24 | The Regents Of The University Of Colorado, A Body Corporate | Compositions and methods for enhancing tolerance for the production of organic chemicals produced by microorganisms |
| WO2008090961A1 (en) | 2007-01-24 | 2008-07-31 | Nippon Shokubai Co., Ltd. | Particulate water-absorbent polymer and process for production thereof |
| WO2008151041A2 (en) | 2007-05-31 | 2008-12-11 | Biolife, Llc | Materials and methods for preparation of alkaline earth ferrates from alkaline earth oxides, peroxides, and nitrates |
| BRPI0815730B1 (en) * | 2007-08-23 | 2020-10-20 | Sumitomo Seika Chemicals Co., Ltd. | method for producing a water-absorbent resin |
| US8048624B1 (en) | 2007-12-04 | 2011-11-01 | Opx Biotechnologies, Inc. | Compositions and methods for 3-hydroxypropionate bio-production from biomass |
| CN101225132B (en) * | 2007-12-20 | 2010-09-01 | 中国科学院长春应用化学研究所 | Method for preparing inverse suspension polymerization polymethacrylic acid moisture-absorption resin |
| PL2239279T3 (en) * | 2008-02-01 | 2013-06-28 | Toagosei Co Ltd | Process for the production of polymer microparticles |
| WO2009096300A1 (en) * | 2008-02-01 | 2009-08-06 | Toagosei Co., Ltd. | Process for the production of polymer microparticles |
| CN102695799A (en) | 2009-09-27 | 2012-09-26 | Opx生物工艺学公司 | Method for producing 3-hydroxypropionic acid and other products |
| US8809027B1 (en) | 2009-09-27 | 2014-08-19 | Opx Biotechnologies, Inc. | Genetically modified organisms for increased microbial production of 3-hydroxypropionic acid involving an oxaloacetate alpha-decarboxylase |
| CN105771945A (en) | 2009-09-29 | 2016-07-20 | 株式会社日本触媒 | Particulate water absorbent and process for production thereof |
| WO2011063363A2 (en) * | 2009-11-20 | 2011-05-26 | Opx Biotechnologies, Inc. | Production of an organic acid and/or related chemicals |
| WO2011065368A1 (en) * | 2009-11-27 | 2011-06-03 | 住友精化株式会社 | Process for production of water-absorbing resin paticles, water-absorbing resin particles, water-stopping material, and absorbent article |
| EP2599796B1 (en) | 2010-07-28 | 2019-01-23 | Sumitomo Seika Chemicals CO. LTD. | Process for production of water-absorbable resin |
| US9234053B2 (en) | 2010-08-18 | 2016-01-12 | Sumitomo Seika Chemicals Co., Ltd. | Process for producing carboxyl-containing polymer composition, and carboxyl-containing polymer composition |
| CN103080140B (en) * | 2010-08-19 | 2014-11-19 | 住友精化株式会社 | Water-absorbing resin |
| PL2615117T3 (en) * | 2010-09-06 | 2021-08-09 | Sumitomo Seika Chemicals Co., Ltd. | Water absorbent resin and method for producing same |
| CA2814797C (en) * | 2010-10-18 | 2017-07-18 | Sumitomo Seika Chemicals Co., Ltd. | Method for producing water-absorbent resin particles and water-absorbent resin particles |
| SG189955A1 (en) | 2010-11-15 | 2013-06-28 | Sumitomo Seika Chemicals | Method for producing water-absorbent resin |
| WO2012081355A1 (en) | 2010-12-16 | 2012-06-21 | 住友精化株式会社 | Method for producing water-absorbing resin |
| JP5637869B2 (en) * | 2011-01-11 | 2014-12-10 | 住友精化株式会社 | Method for producing water absorbent resin |
| JP5798573B2 (en) * | 2011-02-14 | 2015-10-21 | 住友精化株式会社 | Hydrophilic thickener and method for producing the same |
| EP2689020B1 (en) | 2011-03-22 | 2018-05-16 | OPX Biotechnologies Inc. | Microbial production of chemical products and related compositions, methods and systems |
| EP2692741B1 (en) | 2011-03-31 | 2015-12-30 | Sumitomo Seika Chemicals Co. Ltd. | Process for producing water-absorbing resin |
| TWI513713B (en) | 2011-04-21 | 2015-12-21 | Sumitomo Seika Chemicals | Method for producing water-absorbent resin |
| TW201247249A (en) | 2011-04-21 | 2012-12-01 | Sumitomo Seika Chemicals | Water-absorbent resin, absorbent material, and absorbent article |
| EP3398974B1 (en) * | 2011-08-03 | 2022-08-24 | Sumitomo Seika Chemicals Co., Ltd. | Water absorbing resin particles, method for manufacturing water absorbing resin particles, absorption body, absorptive article, and water-sealing material |
| WO2013051417A1 (en) | 2011-10-06 | 2013-04-11 | 住友精化株式会社 | Method for producing water absorbent resin particles |
| WO2013128978A1 (en) * | 2012-02-29 | 2013-09-06 | 住友精化株式会社 | Method for producing water absorbent resin particles |
| JP2013203761A (en) * | 2012-03-27 | 2013-10-07 | Kao Corp | Modified water-absorbing resin particle |
| CA2881666A1 (en) | 2012-08-10 | 2014-02-13 | Opx Biotechnologies, Inc. | Microorganisms and methods for the production of fatty acids and fatty acid derived products |
| KR101595037B1 (en) | 2013-01-15 | 2016-02-17 | 주식회사 엘지화학 | Preparation method for super absorbent polymer |
| KR20150129007A (en) | 2013-03-15 | 2015-11-18 | 카아길, 인코포레이팃드 | Monofunctional mcr + 3-hp dehydrogenase |
| US9512057B2 (en) | 2013-03-15 | 2016-12-06 | Cargill, Incorporated | 3-hydroxypropionic acid compositions |
| US9447438B2 (en) | 2013-03-15 | 2016-09-20 | Cargill, Incorporated | Acetyl-coA carboxylases |
| CN105324457A (en) * | 2013-06-28 | 2016-02-10 | 住友精化株式会社 | Hydrophilic thickener and cosmetic composition |
| US11408013B2 (en) | 2013-07-19 | 2022-08-09 | Cargill, Incorporated | Microorganisms and methods for the production of fatty acids and fatty acid derived products |
| JP6603658B2 (en) | 2013-07-19 | 2019-11-06 | カーギル インコーポレイテッド | Microorganisms and methods for the production of fatty acids and fatty acid derivatives |
| KR20160127742A (en) | 2014-02-28 | 2016-11-04 | 가부시키가이샤 닛폰 쇼쿠바이 | Poly(meth)acrylic acid (salt)-based particulate absorbent, and production method |
| JP5893117B2 (en) | 2014-07-11 | 2016-03-23 | 住友精化株式会社 | Water absorbent resin and absorbent article |
| JP5893116B2 (en) | 2014-07-11 | 2016-03-23 | 住友精化株式会社 | Water absorbent resin and method for producing water absorbent resin |
| JP5689204B1 (en) | 2014-07-11 | 2015-03-25 | 住友精化株式会社 | Water absorbent resin production method, water absorbent resin, water absorbent, absorbent article |
| EP2993228B1 (en) | 2014-09-02 | 2019-10-09 | Cargill, Incorporated | Production of fatty acid esters |
| EP3312218A4 (en) | 2015-06-19 | 2018-06-27 | Nippon Shokubai Co., Ltd. | Poly (meth) acrylic acid (salt) granular water absorbent and method for producing same |
| GB201512725D0 (en) * | 2015-07-20 | 2015-08-26 | Life Technologies As | Polymeric particles |
| US10974223B2 (en) | 2015-12-28 | 2021-04-13 | Nippon Shokubai Co., Ltd. | Method for producing water absorbent resin |
| CN106008779B (en) * | 2016-06-02 | 2018-11-27 | 中北大学 | A kind of crosslinking poly (sodium 4-styrenesulfonate) gel micro-ball production method |
| EP3577227A4 (en) | 2017-02-02 | 2020-12-30 | Cargill Inc. | GENETICALLY MODIFIED CELLS THAT PRODUCE C6-C10 Fatty Acid Derivatives |
| EP3591386B1 (en) | 2017-03-02 | 2023-09-13 | Sumitomo Seika Chemicals Co., Ltd. | Non-destructive method for evaluating structure of water-absorbing resin |
| JPWO2018159800A1 (en) | 2017-03-02 | 2019-12-26 | 住友精化株式会社 | Water absorbent resin and absorbent articles |
| KR20190120219A (en) | 2017-03-02 | 2019-10-23 | 스미토모 세이카 가부시키가이샤 | Absorbent Resin, Soil Repair, and Agricultural Horticulture Materials |
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| CN111902581B (en) | 2018-03-27 | 2023-02-03 | 住友精化株式会社 | Sandbag and manufacturing method thereof |
| CN111885997B (en) * | 2018-03-27 | 2023-05-09 | 住友精化株式会社 | Water-absorbing abrasive, method for producing same, and cosmetic |
| CN108841391B (en) * | 2018-03-30 | 2021-01-29 | 广西科技师范学院 | Preparation method of soil water-retaining agent |
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| FR3101350B1 (en) | 2019-09-26 | 2021-11-12 | Aprotek | Drying material to facilitate recycling of residual concrete |
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| FR3112146B1 (en) | 2020-07-06 | 2023-03-17 | Aprotek | Drying composition to facilitate the transport of oily sludge |
| US20230347318A1 (en) | 2020-07-22 | 2023-11-02 | Sumitomo Seika Chemicals Co., Ltd. | Water-absorbing resin composition, absorbent, and absorptive article |
| KR20230042281A (en) | 2020-07-22 | 2023-03-28 | 스미토모 세이카 가부시키가이샤 | Water-absorbent polymer composition, method for producing the water-absorbent polymer composition, and method for reducing the absorption rate of water-absorbent polymer particles |
| FR3113553B1 (en) | 2020-08-26 | 2023-01-13 | Aprotek | New absorbent and draining article used as a growing medium |
| FR3114980B1 (en) | 2020-10-14 | 2022-12-16 | Aprotek | Drying composition to facilitate the transport of salty sludge |
| WO2022085643A1 (en) | 2020-10-19 | 2022-04-28 | 住友精化株式会社 | Water-absorbing resin, absorber, and absorbent article |
| FR3118031B1 (en) | 2020-12-23 | 2023-11-24 | Aprotek | Composting accelerator |
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| JPWO2022210115A1 (en) | 2021-03-30 | 2022-10-06 | ||
| JPWO2022255301A1 (en) | 2021-05-31 | 2022-12-08 | ||
| KR20240015069A (en) | 2021-05-31 | 2024-02-02 | 스미토모 세이카 가부시키가이샤 | Method for producing absorbent resin, absorbent resin, absorbent body and absorbent article |
| CN114133471B (en) * | 2022-01-14 | 2022-11-25 | 兖矿水煤浆气化及煤化工国家工程研究中心有限公司 | Production method of super absorbent resin |
| FR3133607A1 (en) | 2022-03-16 | 2023-09-22 | Aprotek | Drying composition to facilitate the handling of sludge |
| FR3134388A1 (en) | 2022-04-12 | 2023-10-13 | Aprotek | Drying composition for conditioning digestates |
| KR102630748B1 (en) * | 2023-06-01 | 2024-01-31 | (주)대우건설 | Polymer waterproof material for preventing leakage of reservoir diversion tunnel and their manufacturing method |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4226752A (en) * | 1979-03-28 | 1980-10-07 | Scm Corporation | Emulsion process for polymer particles |
| US4618647A (en) * | 1983-03-11 | 1986-10-21 | Union Carbide Corp. | Process for producing a polymer water-in-oil emulsion |
| CA1248279A (en) * | 1983-03-11 | 1989-01-03 | You-Ling Fan | Dual initiator water-in-oil emulsion polymerization process |
| JPS6187702A (en) * | 1984-10-05 | 1986-05-06 | Seitetsu Kagaku Co Ltd | Production of water-absorptive resin |
| JPH0830098B2 (en) * | 1987-07-16 | 1996-03-27 | 日本合成化学工業株式会社 | Super absorbent resin manufacturing method |
| US4914170A (en) * | 1987-11-17 | 1990-04-03 | Rohm And Haas Company | Superabsorbent polymeric compositions and process for producing the same |
-
1990
- 1990-01-31 JP JP2022774A patent/JP2938920B2/en not_active Expired - Lifetime
-
1991
- 1991-01-03 US US07/637,155 patent/US5180798A/en not_active Expired - Lifetime
- 1991-01-04 TW TW080100073A patent/TW228528B/zh active
- 1991-01-16 CA CA002034293A patent/CA2034293C/en not_active Expired - Lifetime
- 1991-01-25 EP EP91300594A patent/EP0441507B1/en not_active Expired - Lifetime
- 1991-01-25 DE DE69118224T patent/DE69118224T2/en not_active Expired - Lifetime
- 1991-01-25 ES ES91300594T patent/ES2087967T3/en not_active Expired - Lifetime
- 1991-01-29 KR KR1019910001479A patent/KR0174745B1/en not_active Expired - Lifetime
- 1991-01-30 BR BR919100398A patent/BR9100398A/en not_active IP Right Cessation
- 1991-01-31 CN CN91100949A patent/CN1023486C/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| DE69118224T2 (en) | 1996-09-05 |
| CN1023486C (en) | 1994-01-12 |
| TW228528B (en) | 1994-08-21 |
| JPH03227301A (en) | 1991-10-08 |
| CN1053796A (en) | 1991-08-14 |
| ES2087967T3 (en) | 1996-08-01 |
| EP0441507B1 (en) | 1996-03-27 |
| JP2938920B2 (en) | 1999-08-25 |
| KR910014410A (en) | 1991-08-31 |
| EP0441507A1 (en) | 1991-08-14 |
| DE69118224D1 (en) | 1996-05-02 |
| BR9100398A (en) | 1991-10-22 |
| CA2034293A1 (en) | 1991-08-01 |
| KR0174745B1 (en) | 1999-04-01 |
| US5180798A (en) | 1993-01-19 |
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| EEER | Examination request | ||
| MKEX | Expiry |